## Search found 17913 matches

- Thu Aug 25, 2011 10:56 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Period 2 group 1-2 and 6-7 patterns?
- Replies:
**1** - Views:
**211**

### Period 2 group 1-2 and 6-7 patterns?

Question: For period 2, Groups 1-5 (pi 2p bonds come first after 2s*) and Groups 6-7 (sigma 2p comes first instead). Do these patterns apply for the valence electron configurations for the period 3 elements below them, or is there a complication because of the possibility of d-orbitals in an expand...

- Thu Aug 25, 2011 10:56 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: What is exception when the 3d orbitals are lower than 4s?
- Replies:
**1** - Views:
**334**

### Re: What is exception when the 3d-orbitals lower than 4s?

Answer: In general, the 3d orbitals are lower in energy than the 4s orbital, which is why the 4s orbital is always filled before the electrons are placed in the 3d orbitals (if you think about it in terms of the Aufbau, or "building up principle"). The exceptions are chromium and copper. ...

- Thu Aug 25, 2011 10:55 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: What is exception when the 3d orbitals are lower than 4s?
- Replies:
**1** - Views:
**334**

### What is exception when the 3d orbitals are lower than 4s?

Question: What is the exception when the 3d-orbitals would be lower than the 4s-orbitals? Also, what results in half full d^5 subshell?

- Thu Aug 25, 2011 10:54 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Are there exceptions to the order of filling?
- Replies:
**1** - Views:
**257**

### Re: Are there exceptions to the order of filling?

Answer: Copper is an exception to the normal manner of writing electron configurations: it is ([Ar]3d10 4s1). When it loses one electron (Cu+ has net positive charge of 1, resulting from the loss of 1 electron) it loses it from the 4s orbital, because these orbitals are furthest from the nucleus an...

- Thu Aug 25, 2011 10:53 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Are there exceptions to the order of filling?
- Replies:
**1** - Views:
**257**

### Are there exceptions to the order of filling?

Question: When writing electron configurations, how come sometimes there is a configuration like [Ar]3d10 instead of 3d8 4s2. Are there exceptions to the order of filling?

- Thu Aug 25, 2011 10:53 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: How to figure out the number of valence electrons in metals?
- Replies:
**1** - Views:
**364**

### Re: How to figure out the number of valence electrons in met

Answer: This is dependent of the atom you are considering. If for instance you are looking at the transition metals, then the outer most electrons are those in the s and d orbitals. In that case, the number of s and d electrons will be your valence electrons. If you were looking at p block elements...

- Thu Aug 25, 2011 10:53 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: How to figure out the number of valence electrons in metals?
- Replies:
**1** - Views:
**364**

### How to figure out the number of valence electrons in metals?

Question: How do we figure out the number of valence electrons in metals? They seem to be variable.

- Thu Aug 25, 2011 10:52 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Valence e- configuration = Ground state e- configuration?
- Replies:
**1** - Views:
**219**

### Re: valence e- configuration= a ground state e- configuratio

Answer: The valence electron configuration would only require you to say the valence electrons (outermost shell). The ground state electron configuration would require all electrons which can either be written with all orbitals or the noble gas preceding the row in question then the valence electro...

- Thu Aug 25, 2011 10:52 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Valence e- configuration = Ground state e- configuration?
- Replies:
**1** - Views:
**219**

### Valence e- configuration = Ground state e- configuration?

Question: Is the valence electron configuration the same as a ground state electron configuration?

- Thu Aug 25, 2011 10:50 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: electron configuration of both N2 and F2?
- Replies:
**1** - Views:
**8366**

### Re: electron configuration of both N2 and F2?

Answer: F2 the following: (sigma 2s)^2. (sigma 2s*)^2. (sigma 2px)^2. (pi 2py)^2. (pi 2pz)^2. (pi 2px*)^2. (pi 2py*)^2.

N2 the following: (sigma 2s)^2. (sigma 2s*)^2. (pi 2px)^2. (pi 2py)^2. (sigma 2pz)^2.

N2 the following: (sigma 2s)^2. (sigma 2s*)^2. (pi 2px)^2. (pi 2py)^2. (sigma 2pz)^2.

- Thu Aug 25, 2011 10:50 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: electron configuration of both N2 and F2?
- Replies:
**1** - Views:
**8366**

### electron configuration of both N2 and F2?

Question: What is the electron configuration of both N2 and F2, including the x, y, and z of the p-orbitals?

- Thu Aug 25, 2011 10:49 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: How does Cr2+ has 4 unpaired electrons?
- Replies:
**1** - Views:
**12154**

### Re: How does Cr2+ has 4 unpaired electrons?

Answer: The electron configuration for Cr is [Ar]3d6 4s2 (note that 4s is higher in energy than 3d - that is important). Cr2+ means we remove 2 electrons, and we remove them from the highest energy level, which is 4s, so the electron configuration for Cr2+ is [Ar]3d6. The d orbital has 5 orbitals a...

- Thu Aug 25, 2011 10:49 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: How does Cr2+ has 4 unpaired electrons?
- Replies:
**1** - Views:
**12154**

### How does Cr2+ has 4 unpaired electrons?

Question: How does Cr2+ has 4 unpaired electrons? How do you tell in general?

- Thu Aug 25, 2011 10:49 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Cadmium's s and d orbitals are filled, how does Cd2+ exist?
- Replies:
**1** - Views:
**236**

### Re: Cadmium's s and d orbitals are filled, so why there's Ca

Answer: The two 5s e- are removed. Just like Ca or Mg losing two s e- to form Ca2+ and Mg2+. They are all metals.

- Thu Aug 25, 2011 10:48 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Cadmium's s and d orbitals are filled, how does Cd2+ exist?
- Replies:
**1** - Views:
**236**

### Cadmium's s and d orbitals are filled, how does Cd2+ exist?

Question: I would think that Cadmium would not become an ion since its s and d orbitals are filled, so why is it possible for Cd2+ to exist?

- Thu Aug 25, 2011 10:47 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: what would the electron config. of Cu2+ be?
- Replies:
**1** - Views:
**9880**

### Re: what would the electron config. of Cu2+ be?

Answer: Since the electron configuration of Cu is [Ar]3d10 4s1, then Cu2+ is [Ar]3d9.

- Thu Aug 25, 2011 10:47 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: what would the electron config. of Cu2+ be?
- Replies:
**1** - Views:
**9880**

### what would the electron config. of Cu2+ be?

Question: Since we know that the electron configuration of Cu is [Ar]3d10 4s1, what would the electron config. of Cu2+ be?

- Thu Aug 25, 2011 10:47 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Ground state electron configuration of Cu+?
- Replies:
**1** - Views:
**4593**

### Re: ground state electron configuration of Cu+ ?

Answer: As ground state for Cu is [Ar]3d10 4s1, ground state for Cu+ is [Ar]3d10 because we remove the last e- to make the cation.

- Thu Aug 25, 2011 10:46 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Ground state electron configuration of Cu+?
- Replies:
**1** - Views:
**4593**

### Ground state electron configuration of Cu+?

Question: Why is the ground state electron configuration of Cu+ equal to [Ar]3d^10 instead of [Ar]3d8 4s2? I thought that electrons were taken from the s orbital to fill a d orbital only if there are 4 or 9 electrons in the d orbital.

- Thu Aug 25, 2011 10:46 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: full electron configuration for Cr+ ?
- Replies:
**1** - Views:
**11870**

### Re: full electron configuration for Cr+ ?

The valence electron configuration of Cr is 1s2, 2s2, 2p6, 3s2, 3p6, 3d5, 4s1 instead of 1s2, 2s2, 2p6, 3s2, 3p6, 3d4, 4s2 because one of the electron from the s orbital jumped to the d orbital. By distributing its electrons along the empty orbitals, it becomes more stable. Since the ground state fo...

- Thu Aug 25, 2011 10:45 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: full electron configuration for Cr+ ?
- Replies:
**1** - Views:
**11870**

### full electron configuration for Cr+ ?

The full electron configuration for Cr+. The answer was 1s2, 2s2, 2p6, 3s2, 3p6, 3d5. Shouldn't it be 1s2, 2s2, 2p6, 3s2, 3p6, 3d3, 4s2 instead?

- Thu Aug 25, 2011 10:45 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: take out an e- from the 5p before the 5s for In+?
- Replies:
**1** - Views:
**263**

### Re: take out an e- from the 5p before the 5s for In+?

Answer: Since the electrons in 5p have higher energy than the electrons in 5s, the electrons in 5p is removed first. It is no different from why we would remove electrons from the 3p before the 3s orbital.

- Thu Aug 25, 2011 10:45 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: take out an e- from the 5p before the 5s for In+?
- Replies:
**1** - Views:
**263**

### take out an e- from the 5p before the 5s for In+?

Question: Why do you take out an e- from the 5p before the 5s when you did the electron configuration of In+?

- Thu Aug 25, 2011 10:44 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: How to write the electron configuration of a metal cation
- Replies:
**1** - Views:
**199**

### Re: Electron configuration of a metal cation

Answer: First write the e- configuration for the neutral atom. Then remove the last e- that you wrote to get the appropriate e- configuration for the cation.

- Thu Aug 25, 2011 10:44 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: How to write the electron configuration of a metal cation
- Replies:
**1** - Views:
**199**

### How to write the electron configuration of a metal cation

Question: How do you write the electron configuration of a metal cation?

- Thu Aug 25, 2011 10:42 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron configuration for Ag: Ordering 4d and 5s
- Replies:
**1** - Views:
**410**

### Re: Electron configuration for Ag

The 5s should come after the 4d. Once the d orbitals gain electrons, the d orbitals become lower in energy than the 5s, so we list the d orbitals first (since we list the orbitals from lowest to highest energy).

- Thu Aug 25, 2011 10:42 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron configuration for Ag: Ordering 4d and 5s
- Replies:
**1** - Views:
**410**

### Electron configuration for Ag: Ordering 4d and 5s

Question: Why is the e- configuration for Ag [Kr]4d10 5s1 not [Kr]5s1 4d10? Which is written first?

- Thu Aug 25, 2011 10:41 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Valance electrons for d-orbital
- Replies:
**2** - Views:
**228**

### Re: Valance electrons for d-orbital

Answer: Count the # of e- in the s- and d- orbitals for the outer shell. Chromium would have 6 valence electrons.

- Thu Aug 25, 2011 10:41 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Valance electrons for d-orbital
- Replies:
**2** - Views:
**228**

### Valance electrons for d-orbital

Question: How would we determine the number of valence electrons for an element in the d-block (transition elements)? For instance, how many valence are there for Chromium?

- Thu Aug 25, 2011 10:40 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: How do you find valence electrons?
- Replies:
**1** - Views:
**325**

### Re: How do you find valence electrons?

Answer: Valence electrons are the electrons in the outermost shell of the atom, that is the electrons with the highest principle quantum number. For instance Carbon has electrons in the n=2 shell. The electrons in this shell are the valence electrons. Specifically, it has two electrons in the 2s su...

- Thu Aug 25, 2011 10:40 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: How do you find valence electrons?
- Replies:
**1** - Views:
**325**

### How do you find valence electrons?

Question: How do you find valence electrons?

- Thu Aug 25, 2011 10:40 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: (n-1) d-electrons of d-block elements as valence electrons?
- Replies:
**1** - Views:
**353**

### Re: (n-1)d-electrons of d-block elements as valence electron

Answer: Yes, you should consider the (n-1) d-electrons of d-block elements as valence electrons. Cr has 6 valence e-. Count the e- from the previous noble gas.

- Thu Aug 25, 2011 10:39 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: (n-1) d-electrons of d-block elements as valence electrons?
- Replies:
**1** - Views:
**353**

### (n-1) d-electrons of d-block elements as valence electrons?

Question: Do you consider the (n-1) d-electrons of d-block elements as valence electrons? How many valence electrons does Cr have?

- Thu Aug 25, 2011 10:39 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: For a ground state configuration, when is a f-orbital used?
- Replies:
**1** - Views:
**228**

### Re: For a ground state configuration, when is a f-orbital us

Answer: f-orbitals are used in periods 6 & 7. We covered the filling of f-orbitals (Lanthanides and Actinides).

- Thu Aug 25, 2011 10:39 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: For a ground state configuration, when is a f-orbital used?
- Replies:
**1** - Views:
**228**

### For a ground state configuration, when is a f-orbital used?

Question: For a ground state configuration, when is a f-orbital used?

- Thu Aug 25, 2011 10:38 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron config. written with d orbital, excluding s?
- Replies:
**1** - Views:
**181**

### Re: why electron confi are written with d orbital,excluding

Answer: Electron configurations are only written without the s orbitals if you are talking about a transition metal ion which has already lost the electrons in the s orbital. There are special cases (see the column with Cr and Cu) where a single s electron can be promoted to the d orbital.

- Thu Aug 25, 2011 10:38 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron config. written with d orbital, excluding s?
- Replies:
**1** - Views:
**181**

### Electron config. written with d orbital, excluding s?

Question: Could you explain why electron configurations are written with the d orbital, excluding the s orbital (whose electrons are added to the preceding d orbital). Do you always transfer the electrons from the s orbital into the d orbital?

- Thu Aug 25, 2011 10:37 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Don't count the d-orbital electrons as valence electrons?
- Replies:
**1** - Views:
**2733**

### Re: don't count the d-orbital electrons as valence electrons

Answer: Count only the electrons in the same shell, that is, the outermost shell. For Xe and Br the s and p electrons are in the same shell, but d electrons are not in the outermost shell.

- Thu Aug 25, 2011 10:37 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Don't count the d-orbital electrons as valence electrons?
- Replies:
**1** - Views:
**2733**

### Don't count the d-orbital electrons as valence electrons?

Question: Is it just a general rule that you don't count the d-orbital electrons as valence electrons for elements in the p-orbitals? For example, Xe has 8 valence e- rather than 18. Would the element Br only have 7 valence electrons, rather than 17? If this is so, what is the reason?

- Thu Aug 25, 2011 10:36 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: why 4S orbital is filled first than 3d orbital?
- Replies:
**1** - Views:
**380**

### Re: why 4S orbital is filled first than 3d orbital?

Answer: The 4s is lower in energy than the 3d due to its shape and it has e- density closer to the nucleus.

- Thu Aug 25, 2011 10:36 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: why 4S orbital is filled first than 3d orbital?
- Replies:
**1** - Views:
**380**

### why 4S orbital is filled first than 3d orbital?

Question: For electron configurations, why is the 4S orbital filled first than the 3d orbital? Is this connected to orbital's shapes or electron repulsion?

- Thu Aug 25, 2011 10:35 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: [Rn]7s2 6d2 or [Rn]6d2?
- Replies:
**1** - Views:
**724**

### Re: [Rn]7s2 6d2 or [Rn]6d2?

Answer: The two are technically the same, in that they both state that there are 2 electrons in the 7s subshell and the 6d2 subshell. There is a difference in nomenclature as to how to order the orbitals, whether they should be in increasing principle quantum number ([Rn]6d2 7s2) or the way in whic...

- Thu Aug 25, 2011 10:35 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: [Rn]7s2 6d2 or [Rn]6d2?
- Replies:
**1** - Views:
**724**

### [Rn]7s2 6d2 or [Rn]6d2?

Question: Does it matter whether an electronic configuration is written as [Rn]7s2 6d2 or [Rn]6d2?

- Thu Aug 25, 2011 10:35 am
- Forum: Quantum Numbers and The H-Atom
- Topic: How many orbitals are there for n=5?
- Replies:
**1** - Views:
**38459**

### Re: How many orbitals are there for n=5?

Answer: For n=5 we can have l=4, 3, 2, 1, and 0. For each l, we have ml ranging from -l to l. The total number of ml will tell us the number of orbitals. l=4, ml=-4,-3,-2,-1,0,1,2,3,4 for a total of 9 / l=3, ml=-3,-2,-1,0,1,2,3 for a total of 7 / l=2, ml=-2,-1,0,1,2 for a total of 5 / l=1, ml=-1,0,...

- Thu Aug 25, 2011 10:34 am
- Forum: Quantum Numbers and The H-Atom
- Topic: How many orbitals are there for n=5?
- Replies:
**1** - Views:
**38459**

### How many orbitals are there for n=5?

Question: How many orbitals are there for n=5?

- Thu Aug 25, 2011 10:34 am
- Forum: Quantum Numbers and The H-Atom
- Topic: difference between electron orbital and electron subshell?
- Replies:
**2** - Views:
**385**

### Re: difference between electron orbital and electron subshel

Answer: The orbital is determined by the ml value while the subshell is determined by the l value. So if a question asks you how many orbitals there are, it's basically asking how many ml values you can have.

- Thu Aug 25, 2011 10:34 am
- Forum: Quantum Numbers and The H-Atom
- Topic: difference between electron orbital and electron subshell?
- Replies:
**2** - Views:
**385**

### difference between electron orbital and electron subshell?

Question: What is the difference between an electron orbital and an electron subshell?

- Thu Aug 25, 2011 10:32 am
- Forum: Quantum Numbers and The H-Atom
- Topic: What is the pattern for angular momentum quantum numbers?
- Replies:
**1** - Views:
**348**

### Re: What is the pattern for angular momentum quantum numbers

Answer: s orbital means zero angular momentum, p orbital means angular momentum 1, d orbital means angular momentum 2, f orbital means angular momentum 3, and so on

- Thu Aug 25, 2011 10:31 am
- Forum: Quantum Numbers and The H-Atom
- Topic: What is the pattern for angular momentum quantum numbers?
- Replies:
**1** - Views:
**348**

### What is the pattern for angular momentum quantum numbers?

Question: What is the pattern for angular momentum quantum numbers when the orbital is given?

- Thu Aug 25, 2011 10:31 am
- Forum: Quantum Numbers and The H-Atom
- Topic: How many subshells there are in the shell n=4?
- Replies:
**1** - Views:
**8669**

### Re: How many subshells there are in the shell n=4?

Answer: There are 4 subshells: 4s, 4p, 4d, and 4f. When the question asks you about how many subshells there are in a certain shell, what it basically is asking is how many different values of l there are. So if n=4, l can only be 0,1,2,3, which corresponds to s,p,d,f.

- Thu Aug 25, 2011 10:31 am
- Forum: Quantum Numbers and The H-Atom
- Topic: How many subshells there are in the shell n=4?
- Replies:
**1** - Views:
**8669**

### How many subshells there are in the shell n=4?

Question: How many subshells there are in the shell n=4?

- Thu Aug 25, 2011 10:30 am
- Forum: Quantum Numbers and The H-Atom
- Topic: What does the magnetic quantum number find?
- Replies:
**2** - Views:
**331**

### Re: What does the magnetic quantum number find?

Answer: It does not find anything. It simply labels the individual orbitals in a given subshell. All four quantum numbers are meant to designate the identity of an electron in an atom.

- Thu Aug 25, 2011 10:30 am
- Forum: Quantum Numbers and The H-Atom
- Topic: What does the magnetic quantum number find?
- Replies:
**2** - Views:
**331**

### What does the magnetic quantum number find?

Question: What does the magnetic quantum number find?

- Thu Aug 25, 2011 10:30 am
- Forum: *Particle in a Box
- Topic: What is a one dimensional box in regard to a box?
- Replies:
**1** - Views:
**472**

### Re: What is a one dimensional box in regard to a box?

Answer: The one dimensional box means that the particle can only move left or right (in 1-D, in other words, just a line). The distance in which it can move left or right before it hits the walls is L. In other words, the particle in confined within these two walls with a distance of L that it can ...

- Thu Aug 25, 2011 10:29 am
- Forum: *Particle in a Box
- Topic: What is a one dimensional box in regard to a box?
- Replies:
**1** - Views:
**472**

### What is a one dimensional box in regard to a box?

Question: What is a one dimensional box in regards to a particle in a box?

- Thu Aug 25, 2011 10:29 am
- Forum: *Shrodinger Equation
- Topic: Schrodinger equation manipulation and second derivative
- Replies:
**1** - Views:
**477**

### Re: Schrodinger equation manipulation and second derivative

Answer: We did an example of using a wave function in the Schrodinger equation to see what result was obtained for the energy of an electron in an atom. In this example the Schrodinger equation gives us an expression for the energy of an electron. Second derivative is part of the Schrodinger equati...

- Thu Aug 25, 2011 10:29 am
- Forum: *Shrodinger Equation
- Topic: Schrodinger equation manipulation and second derivative
- Replies:
**1** - Views:
**477**

### Schrodinger equation manipulation and second derivative

Question: Does the Schrodinger equation manipulation show that the wave and particle models match up? What does the Schrodinger equation tell us? Why do we take the second derivation of the wave function?

- Thu Aug 25, 2011 10:28 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Equality sign in the uncertainty equation?
- Replies:
**1** - Views:
**218**

### Re: equals sign in the uncertainty equation?

Answer: Use the equal sign to represent the lower limit.

- Thu Aug 25, 2011 10:27 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Equality sign in the uncertainty equation?
- Replies:
**1** - Views:
**218**

### Equality sign in the uncertainty equation?

Question: Sometimes the uncertainty equation has an equal sign instead of of a greater than or equal sign. Is this a typo or is there a reason behind this?

- Thu Aug 25, 2011 10:27 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: plus or minus 1.0 mm per second for the speed. Why x2?
- Replies:
**1** - Views:
**286**

### Re: plus or minus 1.0 mm per second for the speed. Why x2?

Answer: We are interested in the spread when we calculate delta(x) or delta(p). The plus/minus 1 mm/s tells us that if are speed was 15 mm/s, then the possible values would be between 15-1 and 15+1, or 14-16 mm/s. That means there is a 2 mm/s uncertainty in our speed. If it was plus/minus 3, then y...

- Thu Aug 25, 2011 10:27 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: plus or minus 1.0 mm per second for the speed. Why x2?
- Replies:
**1** - Views:
**286**

### plus or minus 1.0 mm per second for the speed. Why x2?

Question: The uncertainty principle and what it means when it says plus or minus 1.0 mm per second for the speed. Why do they multiply this by 2? If it were plus or minus 3.0 mm per second, would it be multiply it by 6 (because it's the spread)?

- Thu Aug 25, 2011 10:26 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: delta(p) x delta(v)=h/(4xpi), why multiply delta v by 2?
- Replies:
**1** - Views:
**522**

### Re: delta px delta v=h/(4xpi), why multiply delta v by 2?

Answer: The Heisenberg indeterminacy principle uses calculations based on indeterminacy, which is twice the uncertainty, or in other words the spread of the uncertainty. For instance, say we had a velocity measurement of 2.00 +/- 0.01 m/s. The spread of possible values for velocity range from 1.99 ...

- Thu Aug 25, 2011 10:25 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: delta(p) x delta(v)=h/(4xpi), why multiply delta v by 2?
- Replies:
**1** - Views:
**522**

### delta(p) x delta(v)=h/(4xpi), why multiply delta v by 2?

Question: For the equation of Heisenberg's uncertainty principle: delta(p) x delta(v)=h/(4xpi), why do we multiply the delta(v) by two to get the correct answer?

- Thu Aug 25, 2011 10:25 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Book uses h-bar/2 instead of h/4pi, which is right?
- Replies:
**1** - Views:
**318**

### Book uses h-bar/2 instead of h/4pi, which is right?

Answer: The textbook uses h-bar, which is h with a little line across the top of it.

h-bar just means h/2pi, so h/4pi is the same as (h-bar)/2.

h-bar just means h/2pi, so h/4pi is the same as (h-bar)/2.

- Thu Aug 25, 2011 10:24 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Book uses h-bar/2 instead of h/4pi, which is right?
- Replies:
**1** - Views:
**318**

### Book uses h-bar/2 instead of h/4pi, which is right?

Question: In the Heisenberg's indeterminacy equation the book uses h-bar/2 instead of h/4pi, which you stated in the course reader. Could you please clarify which is the correct one?

- Thu Aug 25, 2011 10:23 am
- Forum: DeBroglie Equation
- Topic: possible use E=(1/2)mv^2 equation to find the wavelength?
- Replies:
**1** - Views:
**321**

### Re: possible useE=(1/2)mv^2 equation to find the wavelength

Answer: E=(1/2)mv^2 applies to particles with static mass, for example an electron or a base ball. So it cannot be used on photons. E=h(frequency) is valid only for photons. To calculate frequency of electrons or particles other than photons, you must use de Broglie relationship. c=(wavelength x fr...

- Thu Aug 25, 2011 10:23 am
- Forum: DeBroglie Equation
- Topic: possible use E=(1/2)mv^2 equation to find the wavelength?
- Replies:
**1** - Views:
**321**

### possible use E=(1/2)mv^2 equation to find the wavelength?

Question: Would it be possible to use the E=(1/2)mv^2 equation to find the wavelength by substituting E=h(frequency) and c= (wavelength x frequency) instead of using the de Broglie relationship? If not, why is this not possible?

- Thu Aug 25, 2011 10:22 am
- Forum: DeBroglie Equation
- Topic: Broglie relation, all particles have wavelike properties?
- Replies:
**1** - Views:
**343**

### Re: Broglie relation, all particles have wavelike properties

Answer: Actually, electrons do have mass. Its mass is 9.11*10^-31 kg. All waves have particle-like properties, but some not in the sense that you would normally think of for a particle. Like for example, photons (which are light waves) have no "rest mass", which means they have no mass th...

- Thu Aug 25, 2011 10:22 am
- Forum: DeBroglie Equation
- Topic: Broglie relation, all particles have wavelike properties?
- Replies:
**1** - Views:
**343**

### Broglie relation, all particles have wavelike properties?

Question: From the de Broglie relation, all particles have wavelike properties, but all waves don't have particle-like properties, right? (i.e. electron lacks mass).

- Thu Aug 25, 2011 10:21 am
- Forum: DeBroglie Equation
- Topic: Where is the equation v = h/(m*wavelength) derived from?
- Replies:
**1** - Views:
**503**

### Re: Where is the equation v = h/(m*wavelength) derived from?

p=mv and lambda=h/p. The conversion from the work function and Avogadro's number is important, so it should be committed to memory.

- Thu Aug 25, 2011 10:21 am
- Forum: DeBroglie Equation
- Topic: Where is the equation v = h/(m*wavelength) derived from?
- Replies:
**1** - Views:
**503**

### Where is the equation v = h/(m*wavelength) derived from?

Question: Where is the equation v = h/(m*wavelength) derived from? Also, in the same question, are we supposed to know how to convert the work function to energy per particle and the constant 6.022 x 10^23?

- Thu Aug 25, 2011 10:20 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: When to use certain equations?
- Replies:
**5** - Views:
**1086**

### Re: hv=Eupper-Elower or V=R((1/n1^2)-(1/n2^2))

Answer: One result is negative of the other. What value you use for n1 or n2 depends on the question.

- Thu Aug 25, 2011 10:20 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: When to use certain equations?
- Replies:
**5** - Views:
**1086**

### When to use certain equations?

Question: When calculating wavelength or frequency emitted when an electron goes from one n to another n, can I use the hv = E upper-E lower formula? In some of the problems I have been using the Rydberg formula, v=R((1/n1^2)-(1/n2^2)). Is there a right or wrong formula to use for such problems? Or...

- Thu Aug 25, 2011 10:17 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Why multiply the Rydberg Constant by Plank's constant?
- Replies:
**1** - Views:
**329**

### Re: Why multiply the Rydberg Constant by Plank's constant?

Answer: Wavelength is the product of h and frequency, right? The frequency is obtained from the Rydberg's formula, correct? So the two constants R and h appears.

- Thu Aug 25, 2011 10:16 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Why multiply the Rydberg Constant by Plank's constant?
- Replies:
**1** - Views:
**329**

### Why multiply the Rydberg Constant by Plank's constant?

Question: Why is it that you multiply the Rydberg Constant by Plank's constant?

- Thu Aug 25, 2011 10:16 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: How can the following equation be used? E(n)=(-hR)/n^2
- Replies:
**1** - Views:
**239**

### Re: How can the following equation be used? E(n)=(-hR)/n^2

Answer: Energy levels of the H-atom.

- Thu Aug 25, 2011 10:16 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: How can the following equation be used? E(n)=(-hR)/n^2
- Replies:
**1** - Views:
**239**

### How can the following equation be used? E(n)=(-hR)/n^2

Question: How can the following equation be used? E(n)=(-hR)/n^2

- Thu Aug 25, 2011 10:15 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Bohr Frequency to explain the origin of line in spectrums
- Replies:
**1** - Views:
**303**

### Re: use the Bohr Frequency to explain the origin of line in

Answer: The Bohr Frequency corresponds to the energy difference between two levels (see text p 15). This energy difference is the energy of the photon (or frequency or wavelength) that is given off and shows up as a line when doing a spectral analysis.

- Thu Aug 25, 2011 10:05 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Bohr Frequency to explain the origin of line in spectrums
- Replies:
**1** - Views:
**303**

### Bohr Frequency to explain the origin of line in spectrums

Question: How would we use the Bohr Frequency Condition to explain the ORIGIN of lines in spectrums?

- Thu Aug 25, 2011 10:04 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: In Rydberg's formula,which energy level corresponds to n1&n2
- Replies:
**1** - Views:
**359**

### Re: In Rydberg's formula,which energy level corresponds to n

Answer: In general, n1 refers to the lower energy level

- Thu Aug 25, 2011 10:04 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: In Rydberg's formula,which energy level corresponds to n1&n2
- Replies:
**1** - Views:
**359**

### In Rydberg's formula,which energy level corresponds to n1&n2

Question: In Rydberg's formula v=R([1/(n1^2)]-[1/(n2^2)]), which energy level corresponds to n1 and n2? For example, does the initial energy level correspond to n1 and the terminal energy level correspond to n2? Or does the lower energy level - whether it is the initial or the terminal energy level...

- Thu Aug 25, 2011 9:59 am
- Forum: Photoelectric Effect
- Topic: How do we use the work function to find energy?
- Replies:
**1** - Views:
**330**

### Re: How do we use the work function to find energy?

Answer: The work function is determined from the kinetic energy (Ek) of the ejected photon and the energy of the light (hv) applied to the system. Ek=hv-(work function) We can rearrange this to: work function=hv-Ek. Determine the frequency, multiply it by Plank's constant to determine the energy of...

- Thu Aug 25, 2011 9:58 am
- Forum: Photoelectric Effect
- Topic: How do we use the work function to find energy?
- Replies:
**1** - Views:
**330**

### How do we use the work function to find energy?

Question: How do we use the work function to find energy?

- Thu Aug 25, 2011 9:58 am
- Forum: Photoelectric Effect
- Topic: What is the difference between the work function E=hv(nu)?
- Replies:
**1** - Views:
**273**

### Re: What is the difference between the work function E=hv(n

Answer: When the kinetic energy equals zero, they are equivalent.

- Thu Aug 25, 2011 9:58 am
- Forum: Photoelectric Effect
- Topic: What is the difference between the work function E=hv(nu)?
- Replies:
**1** - Views:
**273**

### What is the difference between the work function E=hv(nu)?

Question: What is the difference between and clarify the work function and E=hv? Does that equal the work function?

- Thu Aug 25, 2011 9:57 am
- Forum: Photoelectric Effect
- Topic: work function, why do we divide by Avogadro's number?
- Replies:
**1** - Views:
**345**

### Re: work function, why do we divide by Avogadro's number?

Answer: The work function is kJ/mol, so Avogadro's number is needed to convert moles to particles.

- Thu Aug 25, 2011 9:57 am
- Forum: Photoelectric Effect
- Topic: work function, why do we divide by Avogadro's number?
- Replies:
**1** - Views:
**345**

### work function, why do we divide by Avogadro's number?

Question: For problems using the work function, why do we divide by Avogadro's number?

- Thu Aug 25, 2011 9:56 am
- Forum: Photoelectric Effect
- Topic: E=hv-phi application
- Replies:
**1** - Views:
**5176**

### Re: E=hv-phi application

Answer: The main equation is that E(photon)=Phi+KE, where phi is the work function which is the minimum energy required to remove an electron and KE is the kinetic energy of an electron. Basically the equation is using conservation of energy. The energy given by the photon is used to remove an elec...

- Thu Aug 25, 2011 9:56 am
- Forum: Photoelectric Effect
- Topic: E=hv-phi application
- Replies:
**1** - Views:
**5176**

### E=hv-phi application

Question: The kinetic energy equation E=hv-(work function) can be written E=hv(photon)-hv(ejected). Why is it that if a problem states "Radiation of X Hz is required to eject an electron...," you plug X into the ejected half, whereas if it states "Radiation of X Hz strikes Cs and eje...

- Thu Aug 25, 2011 9:55 am
- Forum: Photoelectric Effect
- Topic: Energy level and Photons
- Replies:
**1** - Views:
**376**

### Re: question on energy level and photon match

Answer: In the first case of excitation of H atom, the energy of the incoming photon is smaller than the ionization energy of H atom. The photon can only excite the electron in H atom from lower energy state to higher energy state. Thus H atoms can only absorb photons with fixed energy. But if the ...

- Thu Aug 25, 2011 9:55 am
- Forum: Photoelectric Effect
- Topic: Energy level and Photons
- Replies:
**1** - Views:
**376**

### Energy level and Photons

Question: How does the energy difference between two energy level and the energy of the incoming photon match in order for the electron in the hydrogen atom to absorb and be excited to the next energy level? If the energy of the photon was greater than (but not great enough to excite the electron i...

- Thu Aug 25, 2011 9:51 am
- Forum: *Black Body Radiation
- Topic: What is "black body radiation?"
- Replies:
**8** - Views:
**1098**

### Re: What is "black body radiation?"

Answer: "Black body radiation" refers to the radiation that originates from the thermal energy of the body that is heated.

- Thu Aug 25, 2011 9:51 am
- Forum: *Black Body Radiation
- Topic: What is "black body radiation?"
- Replies:
**8** - Views:
**1098**

### What is "black body radiation?"

Question: What is "black body radiation"?

- Thu Aug 25, 2011 9:50 am
- Forum: Einstein Equation
- Topic: steps in finding the max wavelength that can break a bond?
- Replies:
**1** - Views:
**1219**

### Re: steps in finding the max wavelength that can break a bon

Answer: First, figure out how much energy is in a single C-C bond because one photon will interact with one bond. To do this, take the energy per mole and divide it by Avogadro's number since there are that many C-C bonds in one mole. From there, set this energy to find a wavelength using the expre...

- Thu Aug 25, 2011 9:50 am
- Forum: Einstein Equation
- Topic: steps in finding the max wavelength that can break a bond?
- Replies:
**1** - Views:
**1219**

### steps in finding the max wavelength that can break a bond?

Question: What are the steps in finding the maximum wavelength needed to break a bond (a C-C bond for example)?

- Thu Aug 25, 2011 9:49 am
- Forum: Properties of Electrons
- Topic: Nuclear charge and electron energies
- Replies:
**1** - Views:
**227**

### Re: Nuclear charge and electrons

Answer: If the electrons are strongly attracted, then the tendency for them to escape deceases. This means that the system becomes more stable and the more stable the system is the lower is its energy. Remember that nature favors stability and low energy.

- Thu Aug 25, 2011 9:45 am
- Forum: Properties of Electrons
- Topic: Nuclear charge and electron energies
- Replies:
**1** - Views:
**227**

### Nuclear charge and electron energies

Question: The greater charge of a nucleus in a many-electron atom, the stronger it attracts the electrons and therefore lowers their energy. Why would an increase in nuclear charge result in lower energy?

- Thu Aug 25, 2011 9:44 am
- Forum: Properties of Electrons
- Topic: What is the formal definition of the "Quantized Property"?
- Replies:
**1** - Views:
**1697**

### Re: What is the formal definition of the "Quantized Property

Answer: Property that has only certain discrete values, and values in between discrete values are not possible.

- Thu Aug 25, 2011 9:44 am
- Forum: Properties of Electrons
- Topic: What is the formal definition of the "Quantized Property"?
- Replies:
**1** - Views:
**1697**

### What is the formal definition of the "Quantized Property"?

Question: What is the formal definition of the "Quantized Property"?

- Thu Aug 25, 2011 9:44 am
- Forum: Properties of Electrons
- Topic: excited state from n=1 to n=3, do they come back down?
- Replies:
**1** - Views:
**302**

### Re: excited state from n=1 to n=3, do they come back down?

Answer: Upon relaxation, both cases are possible for the electron.