Search found 30 matches
- Thu Jun 14, 2018 12:27 am
- Forum: Trends in The Periodic Table
- Topic: Ionization energy vs. Ionic Character
- Replies: 1
- Views: 1008
Ionization energy vs. Ionic Character
What is the difference between ionzation energy and ionic character? (Ionic character was on the last test and I just don't know how it's different from ionization energy)
- Wed Jun 13, 2018 8:37 pm
- Forum: Trends in The Periodic Table
- Topic: Electron affinity: C vs. N
- Replies: 1
- Views: 441
Re: Electron affinity: C vs. N
There's an exception for N and C affinity because of Carbon's half filled subshell being more stable than Nitrogen's full subshell. So C has higher affinity than N. I think Dr. Lavelle said we shouldn't worry about that and to focus on the main trend, which is that electron affinity increases across...
- Wed Jun 13, 2018 8:24 pm
- Forum: Naming
- Topic: Coordination Compounds
- Replies: 3
- Views: 566
Re: Coordination Compounds
Can someone post an example problem of a coordination compound and go through it? I get the concept but not how to write the answer if that makes any sense
- Tue Jun 05, 2018 10:45 pm
- Forum: Hybridization
- Topic: strength of sigma and pi bonds
- Replies: 10
- Views: 1304
Re: strength of sigma and pi bonds
I think a double bond is stronger than a single bond because the two p orbitals overlap and pull the atoms closer together.
- Tue Jun 05, 2018 10:42 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shapes On the Final
- Replies: 3
- Views: 425
Re: Molecular Shapes On the Final
I have this question too! Also, will we need to be able to name different molecules?
- Sun May 27, 2018 11:28 pm
- Forum: Lewis Structures
- Topic: Lone pair arrangement
- Replies: 4
- Views: 626
Re: Lone pair arrangement
I wouldn't worry too much about specific placement, I think figuring out which atom the lone pair is supposed to go on in the first place is the part they'll be grading.
- Sun May 27, 2018 11:25 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Strength
- Replies: 5
- Views: 829
Re: Bond Strength
Two bonds are stronger than one because the molecules are doubly bound to each other by sharing more than one electron.
- Sun May 27, 2018 11:22 pm
- Forum: Ionic & Covalent Bonds
- Topic: Most covalent or ionic character
- Replies: 3
- Views: 1713
Re: Most covalent or ionic character
A molecule that is ionic is going to be least covalent; the two are opposites of each other because requires two molecules to share electrons and the other steals electrons. A smaller difference in electronegativity makes a bond more covalent and a large difference in electronegativity makes a bond ...
- Mon May 21, 2018 11:15 pm
- Forum: Resonance Structures
- Topic: Double bonds
- Replies: 3
- Views: 617
Re: Double bonds
I think double bonds usually end up going on the central atom, but it's not a rule because it can change.
I was also wondering how we know when to use a double bond?
I was also wondering how we know when to use a double bond?
- Mon May 21, 2018 11:14 pm
- Forum: Ionic & Covalent Bonds
- Topic: Formal charge?
- Replies: 12
- Views: 1441
Re: Formal charge?
The equation for finding formal charge is:
Formal Charge= [# of valence electrons on atom]- [lone pair electrons + # of bonds]
Formal Charge= [# of valence electrons on atom]- [lone pair electrons + # of bonds]
- Mon May 21, 2018 11:10 pm
- Forum: Resonance Structures
- Topic: Radicals
- Replies: 13
- Views: 1502
Re: Radicals
A radical is a molecule or atom with an unpaired electron that makes the molecule or atom highly reactive. We use radicals often in cases of resonance because they can stabilize atoms who share the electron.
- Mon May 21, 2018 10:26 pm
- Forum: Ionic & Covalent Bonds
- Topic: Hydrogen bonds vs. dipole-dipole bonds
- Replies: 2
- Views: 384
Re: Hydrogen bonds vs. dipole-dipole bonds
Hydrogen bonding is a type of dipole-dipole bonding. It is the strongest type of non-ionic and non-covalent bond. Dipole-dipole bonds are between any polar molecules and their strength increases as they gain more electrons. Ion-dipole bonds are stronger than both hydrogen bonds and dipole-dipole bon...
- Mon May 14, 2018 11:39 pm
- Forum: Ionic & Covalent Bonds
- Topic: Electronegativity
- Replies: 5
- Views: 744
Re: Electronegativity
It kinda just depends on the type of molecules
- Wed May 09, 2018 9:17 am
- Forum: Balancing Chemical Reactions
- Topic: balancing chemical reactions
- Replies: 7
- Views: 2577
Re: balancing chemical reactions
Some textbooks say an easy way is to start balancing with the element that is present in the least number of equations and to balance products/reactants that are just one element last
- Wed May 09, 2018 9:13 am
- Forum: Ionic & Covalent Bonds
- Topic: Periodic Trends
- Replies: 3
- Views: 444
Periodic Trends
How are the trends different in the periodic table between ionic radii and covalent radii?
- Wed May 09, 2018 12:57 am
- Forum: Trends in The Periodic Table
- Topic: Electron Affinity Exceptions
- Replies: 3
- Views: 649
Re: Electron Affinity Exceptions
The practice midterm has several questions about atomic radius and electron affinity so I would definitely review them!
- Wed May 09, 2018 12:54 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: E=R(1/n-1/n)?
- Replies: 7
- Views: 1090
Re: E=R(1/n-1/n)?
Are we supposed to use E= R(1/n-1/n) or E= hR/n^2 when finding the difference in energy levels?
- Tue May 08, 2018 9:50 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Order of Orbitals
- Replies: 3
- Views: 467
Order of Orbitals
What is the order of the orbitals for an element like Cu or Ba that is has a large atomic number? (by order I mean like 2s, 2p, 3d... and any exceptions)
- Sun Apr 29, 2018 11:14 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Radius
- Replies: 3
- Views: 389
Re: Radius
When the electron is at a higher energy level, it is further from the nucleus, so it's radius has changed. Because of this, if an electron's energy changes it is likely the radius will change as well.
- Sun Apr 29, 2018 11:11 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: The concept of Orbitals
- Replies: 12
- Views: 1091
Re: The concept of Orbitals
An orbital corresponds to the wavefunction of each atom, which is measured by a mathematical equation. The schrodinger equation calculates wavefunction and the corresponding energy, which is what ties orbitals to different energy levels.
- Tue Apr 24, 2018 1:49 am
- Forum: Properties of Light
- Topic: Diffraction Patterns
- Replies: 3
- Views: 815
Diffraction Patterns
One of the post-module questions is: 19. What causes a diffraction pattern? A. Slit in the barrier works as a filter to create a diffraction pattern. B. Different wavelengths which the light composes. C. Different intensities of a light wave D. Two or more waves interacting constructively and destru...
- Sun Apr 22, 2018 10:55 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Negative signs
- Replies: 3
- Views: 411
Re: Negative signs
I'm confused about this too...
I know the Rydberg equation is used to figure out the wavelength of a line in the hydrogen spectrum. The value isn't usually going to be negative because a bigger number is always subtracting a smaller number (1/2-1/4 for example).
I know the Rydberg equation is used to figure out the wavelength of a line in the hydrogen spectrum. The value isn't usually going to be negative because a bigger number is always subtracting a smaller number (1/2-1/4 for example).
- Sun Apr 22, 2018 10:48 pm
- Forum: Photoelectric Effect
- Topic: Application of different formulas [ENDORSED]
- Replies: 4
- Views: 513
Application of different formulas [ENDORSED]
Can someone post a list with all of the formulas and what we use each one for? For example, we use E=hv to calculate the energy of a photon.
- Fri Apr 20, 2018 1:11 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Heisenberg Equation & Test 2
- Replies: 4
- Views: 485
Re: Heisenberg Equation & Test 2
Don't think so- Test 2 only covers until 1.5, which includes calculating wavelength and frequency, identifying lines in the hydrogen spectrum, planck's constant and calculating the energy of a photon, and calculating wavelength with the de Broglie equation. It does not include the Heisenberg equatio...
- Sun Apr 15, 2018 11:31 pm
- Forum: Einstein Equation
- Topic: Different equations
- Replies: 4
- Views: 538
Re: Different equations
I'm struggling with the same thing haha. What I do is always try to determine what the question is asking for and what is given. Then you can determine which equation(s) you can use to find your answer. Right now the most important equations are: Kinetic Energy: 1/2mv^2 (or Ek)= hv-work function Pla...
- Sun Apr 15, 2018 11:21 pm
- Forum: Photoelectric Effect
- Topic: Threshold Energy [ENDORSED]
- Replies: 12
- Views: 1820
Re: Threshold Energy [ENDORSED]
The threshold energy is the minimum amount of energy required to move an electron from the surface of a metal.
- Sun Apr 15, 2018 10:11 pm
- Forum: Photoelectric Effect
- Topic: Example 1.5 [ENDORSED]
- Replies: 8
- Views: 981
Example 1.5 [ENDORSED]
(a) of this example asks you to find the kinetic energy of the ejected electron. The problem gives you the speed of an electrom emitted from the surface of potassium by a photon as 668 km/s. Using the equation E=mv^2, how do you know that m is 9.109 x 10^-31kg? Do you use the molar mass of potassium...
- Sun Apr 15, 2018 8:14 pm
- Forum: Photoelectric Effect
- Topic: Intensity
- Replies: 1
- Views: 200
Intensity
I was wondering if someone could explain how to 1. find the intensity of radiation and 2. explain in what situations you would need to find the intensity
- Mon Apr 09, 2018 6:47 pm
- Forum: SI Units, Unit Conversions
- Topic: Avagrado's Number [ENDORSED]
- Replies: 6
- Views: 1137
Re: Avagrado's Number [ENDORSED]
6.022x10^23 represents the number of objects per mole. It can be used to calculate the number of atoms or molecules in a given number of moles. So atoms and molecules are used interchangeably for Avogadro's Number.
- Mon Apr 09, 2018 6:41 pm
- Forum: SI Units, Unit Conversions
- Topic: Sig figures
- Replies: 9
- Views: 605
Re: Sig figures
How do you know how many decimals to use? For example, if I had 2.0 moles x 134.6 g, how many decimals should my answer have?