## Search found 37 matches

Sun Nov 15, 2020 8:12 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Textbook 1E#9
Replies: 3
Views: 16

### Re: Textbook 1E#9

Daniela_Martinez_3B wrote:Yes, you're correct for part a! For part b, it's invalid because l=0 so ml must also equal 0. Part c is also invalid because the maximum value l can have is n-1 and n=4 so lmax=3.

Thank you! How do you get ml from l? Like why does l=0 restrict the value of ml?
Sun Nov 15, 2020 8:09 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Textbook 1E#17
Replies: 3
Views: 15

### Re: Textbook 1E#17

Jillian Labador 2F wrote:Hi! I believe the electron configuration for Manganese (Mn) is [Ar] 3d^5 4s^2 so an electron would be removed from the 4s orbital to form Mn+

This is very helpful, but why is it 3d^5 instead of 3d^10?
Sun Nov 15, 2020 5:26 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Textbook 1E#17
Replies: 3
Views: 15

### Textbook 1E#17

For each of the following ground-state atoms, predict the type of orbital (1s, 2p, 3d, 4f, etc.) from which an electron will be removed to form the +1 ion: (a) Ge; (b) Mn; (c) Ba; (d) Au.

For part b, why is the 4s removed and not the 4p? Is my electron configuration wrong? [Ar]4s^2 4p^5
Sun Nov 15, 2020 5:12 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Textbook 1E#11
Replies: 4
Views: 19

### Textbook 1E#11

Write the ground-state electron configuration for each of the following atoms: (a) sodium; (b) silicon; (c) chlorine; (d) rubidium.

I understand how to do this, but how come 5s^1 comes before 4d^1 and how do we know when to do this?
Sun Nov 15, 2020 5:04 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Textbook 1E#9
Replies: 3
Views: 16

### Textbook 1E#9

Of the following sets of four quantum numbers {n, l, ml, ms}, identify the ones that are forbidden for an electron in an atom and explain why they are invalid: (a) {4,2,−1,+1/2}; (b) {5,0,−1,+1/2}; (c) {4,4,−1,+1/2}. For part a it would be 4d where ml could be -2, -1, 0, 1, or 2, and -1 is given so ...
Sun Nov 15, 2020 4:55 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Chapter 2 HW: #39 [ENDORSED]
Replies: 8
Views: 2189

### Re: Chapter 2 HW: #39[ENDORSED]

Karla_Coronado_1J wrote:Determine whether each of the following electron configurations represents the ground state or an excited state of the atom given.

Thank you!

How is Pauli's exclusion principle seen on in these pictures?
Sun Nov 15, 2020 4:38 pm
Forum: Quantum Numbers and The H-Atom
Topic: Textbook 1D#23
Replies: 1
Views: 20

### Textbook 1D#23

How many orbitals can have the following quantum numbers in an atom: (a) n=2, l=1; (b) n=4, l=2, ml=−2; (c) n=2; (d) n=3, l=2, ml=+1? I know how to do part a, but I am confused on how the ml affects the number of orbitals, can someone please explain? Also for part c, how do we find the number of orb...
Sun Nov 15, 2020 4:28 pm
Forum: Quantum Numbers and The H-Atom
Topic: Textbook 1D#17
Replies: 3
Views: 13

### Textbook 1D#17

For each orbital listed (a) 6p; (b) 3d; (c) 2p; (d) 5f, give the possible values of the magnetic quantum number.

Do we just have to memorize what magnetic quantum numbers go with each orbital or is there a way to figure it out?
Sun Nov 15, 2020 4:23 pm
Forum: Quantum Numbers and The H-Atom
Topic: Homework questions 2.21 and 2.27
Replies: 5
Views: 2048

### Re: Homework questions 2.21 and 2.27

As an example of 3d this is another way of writing (n)(l) since n = 3 and l = 2 = d for all angular momentum quantum numbers we have l=0; s l=1; p l=2; d l=3; f l=4; g for the first question (a) 6p; (b) 3d; (c) 2p; (d) 5f (a) n =6 and l = 1 (b) n = 3 and l = 2 (c) n = 2 and l = 1 (d) n = 5 and l = ...
Sun Nov 15, 2020 4:16 pm
Forum: Quantum Numbers and The H-Atom
Topic: Textbook 1D#13
Replies: 2
Views: 22

### Textbook 1D#13

) How many values of the quantum number l are possible when n=7? (b) How many values of ml are allowed for an electron in a 6d-subshell? (c) How many values of ml are allowed for an electron in a 3p-subshell? (d) How many subshells are there in the shell with n=4? I am confused on part b. I know l i...
Sun Nov 15, 2020 4:08 pm
Forum: Quantum Numbers and The H-Atom
Topic: HW question 2.17 [ENDORSED]
Replies: 7
Views: 930

### Re: HW question 2.17[ENDORSED]

The question states" How many orbitals are in sub-shells will l equal to a)0 b)2 c)1 d)3" for a) you know that L=0 corresponds to a s-orbital and s orbitals have 1orbital therefore the answer is 1 orbital b) l=2 corresponds to a d-orbital and d orbitals have 5 orbitals , therefore the ans...
Wed Nov 11, 2020 5:29 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Sapling #9
Replies: 5
Views: 36

### Re: Sapling #9

The sum of oxidation numbers for each element must add up to the overall charge of the molecule (so in this case, it should equal -1). Oxygen has an oxidation of -2, and since there are four oxygen atoms, the sum of oxidation states for oxygen is -8. Now, you can pick an oxidation state for the chl...
Wed Nov 11, 2020 5:23 pm
Forum: Dipole Moments
Topic: Sapling #17
Replies: 7
Views: 51

### Sapling #17

Which molecules exhibit only London (dispersion) forces? CH3F BCl3 Br2 NH3 CH4 Where do I begin with this question? I'm confused on what London (dispersion) forces are? I think they may have been called something else in lecture. I know Br2 is one of them because it doesn't have any dipole moment.
Wed Nov 11, 2020 5:18 pm
Forum: Electronegativity
Topic: Sapling #14
Replies: 10
Views: 54

### Sapling #14

Acetone can form hydrogen bonds with water. Select which image represents an acetone molecule interacting with a water molecule.

The hint says there must be an O on either side of the H in the H-bond, why is this?
Wed Nov 11, 2020 5:01 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Sapling #9
Replies: 5
Views: 36

### Sapling #9

What is the oxidation number of chlorine in the perchlorate ion? (ClO4-)

How do I figure the oxidation number out?
Thu Oct 29, 2020 9:55 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Sapling #13
Replies: 3
Views: 36

### Sapling #13

How many electrons in an atom could have these sets of quantum numbers?
n=2
n=4,l=1
n=7,l=3,ml=−1

Tue Oct 27, 2020 10:14 pm
Forum: DeBroglie Equation
Topic: Book Problem B21
Replies: 3
Views: 21

### Book Problem B21

A baseball must weigh between 5.00 and 5.25 ounces (1 ounce = 28.3g). What is the wavelength of a 5.15-ounce baseball thrown at 92 mph? I found the answer but it is a little off in the scientific notation. I converted oz to grams and 92 mph to 41.1277 m/s. I did wavelength = h/145.745g*41.1277 m/s. ...
Tue Oct 27, 2020 10:08 pm
Forum: Properties of Electrons
Topic: Book Problem B15
Replies: 3
Views: 42

### Re: Book Problem B15

[quote="haley f"]The velocity of an electron that is emitted from a metallic surface by a photon is 3.6×10^3 km⋅s−1. (a) What is the wavelength of the ejected electron? (b) No electrons are emitted from the surface of the metal until the frequency of the radiation reaches 2.50×10^16Hz. How...
Tue Oct 27, 2020 9:46 pm
Forum: Properties of Electrons
Topic: Book Problem B15
Replies: 3
Views: 42

### Book Problem B15

The velocity of an electron that is emitted from a metallic surface by a photon is 3.6×10^3 km⋅s−1. (a) What is the wavelength of the ejected electron? (b) No electrons are emitted from the surface of the metal until the frequency of the radiation reaches 2.50×10^16Hz. How much energy is required to...
Mon Oct 26, 2020 10:55 pm
Forum: Molarity, Solutions, Dilutions
Topic: Concentration Calculations
Replies: 10
Views: 2977

### Re: Concentration Calculations

Alright finding the molarity is the first step. For the Na2CO3 molarity is 0.08 M. You might want to convert the values from mmol to mols. but 1 mmol= .001 mol. To find a) you convert the mmol to mol to get 0.002015 mole Na. Since theres 2 Na's in Na2CO3 the molarity is gonna be twice so instead of...
Sat Oct 24, 2020 3:36 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Molar Mass and Metal/Sulfides
Replies: 4
Views: 3613

### Re: Molar Mass and Metal/Sulfides

Leyla Anwar 1C wrote:Hi, where does the 32.05 come from? Is that how to make any metal a sulfide? Or is that specific to Ca?

I was wondering the same thing! Here's what I found: Calcium sulfide is Ca and S so the 32.05 is simply the molar mass of sulfur!
Fri Oct 23, 2020 1:54 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Sapling 2/3/4 #26
Replies: 2
Views: 42

### Re: Sapling 2/3/4 #26

Hi! I actually kept messing this part up too. This is how I ended up finding the mass of a single Helium atom. The tricky part of dimensional analysis is the units and cancelling them out accordingly. To solve for the uncertainty in the helium atom's velocity, we plug that into the equation h/(4pi)...
Thu Oct 22, 2020 11:03 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Sapling 2/3/4 #26
Replies: 2
Views: 42

### Sapling 2/3/4 #26

What is the minimum uncertainty in a helium atom's velocity if the position is known within 1 angstrom? I figured out the correct answer for the first part of the problem asking about the electron but I am stuck on the second part. I think I am having a hard time with the conversions of the mass of ...
Thu Oct 22, 2020 10:19 pm
Forum: Properties of Light
Topic: Sapling #10
Replies: 8
Views: 127

### Re: Sapling #10

The mass of a single fluorine molecule is what is listed on the periodic table of elements. Since it is diatomic, you should double the amu. To get the correct wavelength, you have to convert the g/molecule into kg/molecule. Then using, wavelenth=h/(mv), the kg in the m will cancel with the kg in p...
Thu Oct 22, 2020 10:07 pm
Forum: Photoelectric Effect
Topic: Sapling HW Weeks 2, 3, 4 Question #9
Replies: 10
Views: 95

### Re: Sapling HW Weeks 2, 3, 4 Question #9

Hi. Can someone help me solve this problem? I'm not sure what I should solve for first if I'm just given the work function. As you may well know, placing metal objects inside a microwave oven can generate sparks. Two of your friends are arguing over the cause of the sparking, with one stating that ...
Thu Oct 22, 2020 10:03 pm
Forum: Photoelectric Effect
Topic: Sapling HW Weeks 2, 3, 4 Question #9
Replies: 10
Views: 95

### Re: Sapling HW Weeks 2, 3, 4 Question #9

The maximum wavelength of the radiation that will eject electrons occurs when the energy of the incident light equals the work function. When you are given the work function, you can calculate the wavelength of the radiation. work function = E(photon) = hc/(wavelength) Does this mean that whenever ...
Thu Oct 22, 2020 9:10 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Sapling 2/3/4 #6
Replies: 2
Views: 25

### Sapling 2/3/4 #6

Will we only need to know this equation for a hydrogen atom? The En=-(hR)/n^2 equation. And from this equation how do we determine how many spectral lines there will be?
Sat Oct 17, 2020 9:05 pm
Forum: Properties of Electrons
Topic: Wave Properties of Electrons
Replies: 6
Views: 34

### Re: Wave Properties of Electrons

Prof Lavelle said this was unexpected, so does that mean that electrons don't always have wavelike properties?
Sat Oct 17, 2020 9:04 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: delta E
Replies: 10
Views: 59

### Re: delta E

Is delta E always equal to the Energy of the photon like in the example from Friday's lecture?
Sat Oct 17, 2020 9:02 pm
Forum: Photoelectric Effect
Topic: Sapling #4 Homework Part 2
Replies: 9
Views: 114

### Re: Sapling #4 Homework Part 2

Divide the total energy by the work function to see how many electrons the energy can displace. 6.78×10−7 J/4.28494×10−19 J/photon Important concepts: One photon with enough energy to displace an electron will only displace one electron. In other words, there is a one-photon to one electron ratio i...
Tue Oct 13, 2020 7:29 pm
Forum: Properties of Light
Topic: Sapling Week 2/3 question 4
Replies: 9
Views: 102

### Sapling Week 2/3 question 4

So for this question would we use the equation E(photon) - E(energy to remove e-) = E(excess)? And in this case E(energy to remove e-) is the work function that the question is asking for? And do you set the equation (E(photon) - E(energy to remove e-)) equal to the maximum kinetic energy? Here's th...
Mon Oct 12, 2020 10:50 am
Forum: Properties of Light
Topic: Quantized
Replies: 11
Views: 58

### Quantized

Does quantized just mean focusing on the individual molecules or photons rather than the continuous flow of water or light?
Thu Oct 08, 2020 3:13 pm
Forum: Administrative Questions and Class Announcements
Topic: Step Up Sessions
Replies: 71
Views: 4387

### Re: Step Up Sessions

Who are the Step up Sessions taught by? And are they helpful?
Thu Oct 08, 2020 3:11 pm
Forum: SI Units, Unit Conversions
Topic: Sig figs and molar mass
Replies: 18
Views: 93

### Sig figs and molar mass

When taking the molar masses off the periodic table, how many decimal points do we need to use? Is it generally okay to use 1 for Hydrogen and 12 for Carbon?
Thu Oct 08, 2020 3:09 pm
Forum: Empirical & Molecular Formulas
Topic: Sapling Question Number 8
Replies: 7
Views: 61

### Re: Sapling Question Number 8

AMU and molar mass are equivalent so no need to do any conversions!
Wed Oct 07, 2020 8:30 pm
Forum: Empirical & Molecular Formulas
Topic: Sapling Question Number 9
Replies: 12
Views: 179

### Re: Sapling Question Number 9

How I did this problem: 2.275g CO2= 0.05169 mol CO2 = 0.05169 mol C =0.6194 g C 0.929g H2O= 0.05157 mol H2O = 0.1031 mol H = 0.1040 g H 1.00 g capra - (0.6194 g C + 0.1040 g H) = 0.28 g O = 0.017 mol O 0.017 mol O --> 1 0.05169 mol C --> 3 0.1031 mol H --> 6 C3H6O *2 to get molecular formula based ...
Wed Oct 07, 2020 8:23 pm
Forum: Limiting Reactant Calculations
Topic: Sapling Question #10
Replies: 9
Views: 124

### Re: Sapling Question #10

This was all super helpful, thank you so much!