Search found 35 matches

by Joanne Lee 1I
Tue Nov 12, 2019 5:16 pm
Forum: Bond Lengths & Energies
Topic: Boiling and Melting points
Replies: 6
Views: 18

Re: Boiling and Melting points

I don't think you need to know the specific boiling and melting points of each type of interaction but just know how the interaction affect the boiling and melting points and which ones might have higher or lower boiling and melting points.
by Joanne Lee 1I
Tue Nov 12, 2019 4:44 pm
Forum: Resonance Structures
Topic: Point of Resonance Structures
Replies: 2
Views: 16

Re: Point of Resonance Structures

Even though the structures we draw don't exist, finding the Lewis structure most similar to the actual molecule allows us to better see what the molecule might look like and how strong and how long the bonds are between each element.
by Joanne Lee 1I
Tue Nov 12, 2019 4:35 pm
Forum: Resonance Structures
Topic: Writing Out Resonance
Replies: 3
Views: 14

Re: Writing Out Resonance

I think if you need to express resonance, the teacher is asking you to draw out all possible resonance structures.
by Joanne Lee 1I
Tue Nov 12, 2019 4:31 pm
Forum: Lewis Structures
Topic: Xenon
Replies: 4
Views: 22

Re: Xenon

Any element in period 3 or beyond has access to their respective d orbital so they are able to have/ accept extra electrons and put it in their empty d orbital.
by Joanne Lee 1I
Tue Nov 12, 2019 4:23 pm
Forum: Dipole Moments
Topic: 3F.3
Replies: 5
Views: 30

Re: 3F.3

Dipole-dipole interactions are only important for CH3Cl, CH2Cl2, and CHCl3 because these molecules are polar whereas CH4 and CCl4 are nonpolar. Only polar molecules have dipole-dipole moments so it is only significant for those three molecules.
by Joanne Lee 1I
Wed Nov 06, 2019 11:47 pm
Forum: Resonance Structures
Topic: Bond lengths
Replies: 11
Views: 50

Re: Bond lengths

The bond lengths are the same value because the actual structure is a mixture of all the different versions of the resonance structure. Therefore, it isn't just one that has a double bond and the rest a single bond but all the bonds are a mixture of both, making the bond length in between the value ...
by Joanne Lee 1I
Wed Nov 06, 2019 11:43 pm
Forum: Bond Lengths & Energies
Topic: Why Are Double Bonds Shorter
Replies: 16
Views: 120

Re: Why Are Double Bonds Shorter

Double bonds are shorter than single bonds because double bonds are stronger and therefore pull the electrons closer together in the two elements which decreases the length of the bond.
by Joanne Lee 1I
Wed Nov 06, 2019 11:41 pm
Forum: Bond Lengths & Energies
Topic: Midterm
Replies: 9
Views: 83

Re: Midterm

It should take about a week for the midterm to be graded.
by Joanne Lee 1I
Wed Nov 06, 2019 11:41 pm
Forum: Bond Lengths & Energies
Topic: Bond lengths
Replies: 4
Views: 19

Re: Bond lengths

Bond length is dependent on the type of bond, whether it is a single bond, double bond, or triple bond. Then if each molecule has resonance the bond lengths will be in between the lengths of the two different bonds. We have not been taught how to specifically find the exact value of the bond length.
by Joanne Lee 1I
Wed Nov 06, 2019 11:38 pm
Forum: Bond Lengths & Energies
Topic: Midterm
Replies: 8
Views: 58

Re: Midterm

There are supposed to be eight questions on the midterm but there are multiple parts to each question.
by Joanne Lee 1I
Wed Oct 30, 2019 3:19 pm
Forum: Octet Exceptions
Topic: Radicals
Replies: 9
Views: 42

Re: Radicals

In order to identify if a species is a radical, just count the total number of valence electrons in that molecule and if it is an odd number, it is a radical.
by Joanne Lee 1I
Wed Oct 30, 2019 3:13 pm
Forum: Lewis Structures
Topic: Bonds:
Replies: 3
Views: 16

Re: Bonds:

Each bond line is two electrons shared between elements.
by Joanne Lee 1I
Wed Oct 30, 2019 3:12 pm
Forum: Octet Exceptions
Topic: Can P,S,Cl have less than 8 electrons?
Replies: 3
Views: 23

Re: Can P,S,Cl have less than 8 electrons?

Usually P, S, and Cl don't have less than eight electrons because they are not stable until they complete their octet or exceed it. Therefore, while it is unstable, it will always be trying to react with other elements until it becomes stable.
by Joanne Lee 1I
Wed Oct 30, 2019 3:10 pm
Forum: Ionic & Covalent Bonds
Topic: Format of midterm?
Replies: 12
Views: 56

Re: Format of midterm?

Like our first test, I'm pretty sure the test will all be free response because the practice midterm given to us by the UA's is also all free responses.
by Joanne Lee 1I
Wed Oct 30, 2019 3:06 pm
Forum: Ionic & Covalent Bonds
Topic: Likely Charge for Ions to Form
Replies: 3
Views: 15

Re: Likely Charge for Ions to Form

The most likely charge for an atom to form is based on the number of valence electrons of each element. For example, Na has one valence electron so it would be more likely to give that one electron up than try and collect seven more. Therefore it has a likely charge of +1. On the other hand, P has f...
by Joanne Lee 1I
Tue Oct 22, 2019 9:47 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration
Replies: 4
Views: 27

Re: Electron Configuration

Adding x, y, or z states specifically the orientation of the orbital and where it lies on a 3D (x,y,z) graph.
by Joanne Lee 1I
Tue Oct 22, 2019 9:44 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Spin
Replies: 8
Views: 46

Re: Electron Spin

When you are filling out an orbital, know that each orbital must have one electron before the electrons are paired. This is because electrons prefer to be in different orbitals due to their negative charge that repels other electrons. So for example, if four electrons are in the p orbital there woul...
by Joanne Lee 1I
Tue Oct 22, 2019 9:41 pm
Forum: Quantum Numbers and The H-Atom
Topic: The plus and minus sign on the magnetic quantum #
Replies: 5
Views: 28

Re: The plus and minus sign on the magnetic quantum #

You should write the plus sign just to signify specifically which way the electron is spinning.
by Joanne Lee 1I
Tue Oct 22, 2019 9:39 pm
Forum: Quantum Numbers and The H-Atom
Topic: 1D.13
Replies: 3
Views: 30

Re: 1D.13

So because you know it is the d orbital, you know l= 2. To determine the ml value, know that ml equals the range of value from -l to l. Therefore, in this case, the values of ml would be -2, -1, 0, 1, and 2.
by Joanne Lee 1I
Tue Oct 22, 2019 9:36 pm
Forum: Quantum Numbers and The H-Atom
Topic: Electrostatic potential energy
Replies: 3
Views: 11

Re: Electrostatic potential energy

In this equation, q1 and q2 is the value of the charge of the two electrons.
by Joanne Lee 1I
Tue Oct 15, 2019 6:12 pm
Forum: Properties of Light
Topic: Homework
Replies: 11
Views: 37

Re: Homework

Yes, you will still receive full credit, as long as they are all problems that were assigned based on the syllabus.
by Joanne Lee 1I
Tue Oct 15, 2019 6:10 pm
Forum: Properties of Light
Topic: MidTerms and Finals
Replies: 11
Views: 71

Re: MidTerms and Finals

Both the midterms and finals will be administered at a different time than lecture and discussion times. For example, the midterm is from 6PM - 8PM on Novemebr 6.
by Joanne Lee 1I
Tue Oct 15, 2019 6:08 pm
Forum: Einstein Equation
Topic: E=hv
Replies: 41
Views: 1449

Re: E=hv

The E represents the amount of energy of a photon but you can always compare that E value to the work function value to determine whether the E amount is enough to remove the electron from one shell to another.
by Joanne Lee 1I
Tue Oct 15, 2019 6:05 pm
Forum: Properties of Electrons
Topic: Photons
Replies: 9
Views: 58

Re: Photons

Yes, there can be cases where the photons do not have enough energy to eject an electron. If there is not enough energy, then the electron will stay in whatever orbital it is currently in and will not jump to the other orbitals.
by Joanne Lee 1I
Tue Oct 15, 2019 6:03 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Time of Use
Replies: 5
Views: 35

Re: Time of Use

For questions that require you to use Heisenberg equation, the question will have the words uncertainty in position, velocity, or momentum. If these words are not stated in the question, then you should not use Heisenberg's equation.
by Joanne Lee 1I
Thu Oct 10, 2019 2:00 pm
Forum: Properties of Light
Topic: Atom's transition
Replies: 3
Views: 20

Re: Atom's transition

A greater energy difference implies greater frequency because energy and frequency are proportional to each other. As one increases, the other does as well and vice versa based on the equation E = hv.
by Joanne Lee 1I
Thu Oct 10, 2019 1:55 pm
Forum: DeBroglie Equation
Topic: DeBroglie Units
Replies: 3
Views: 256

Re: DeBroglie Units

You also need to remember that you are dividing Planck's constant by the momentum and the units for Plank's constant is J(s) where Joules is kg⋅m2⋅s−2. So, in order for the two masses units to cancel out, you have to use kg in the denominator as well. It's always about using the same units as the co...
by Joanne Lee 1I
Thu Oct 10, 2019 1:50 pm
Forum: Properties of Electrons
Topic: Balmer/Lyman series
Replies: 5
Views: 36

Re: Balmer/Lyman series

I think that's something you should get familiar with. Especially the Balmer and Lyman series since Lavelle specifically went over those two in class.
by Joanne Lee 1I
Thu Oct 10, 2019 1:48 pm
Forum: Properties of Light
Topic: Question 1.A.3
Replies: 4
Views: 30

Re: Question 1.A.3

The extent of the change in the electrical field is referring to the slope of the waves and so as the frequency decreases, the waves of would be broader and more spread out, therefore meaning that the slopes of the waves would be less steep. This decrease in the slope means that the extent of the ch...
by Joanne Lee 1I
Mon Oct 07, 2019 10:33 pm
Forum: Photoelectric Effect
Topic: Post Module Assessment
Replies: 1
Views: 24

Post Module Assessment

For number 25, it states that the photoelectric experiments gave rise to a new equation relating the energy of light to its frequency. Select the right equation.
A. c = λ x v
B. Ek = 1/2(MV²)
C. MV²/2 = hv - φ
D. E = hv
E. None of the above

Which one is the correct answer? Thank you!
by Joanne Lee 1I
Wed Oct 02, 2019 1:07 am
Forum: Significant Figures
Topic: Lecture on Sig Figs?
Replies: 4
Views: 37

Lecture on Sig Figs?

Hey everyone! I heard that there would be a lecture that includes sig figs, does anyone know if this is true or should I just go ahead and review it on my own?
by Joanne Lee 1I
Wed Oct 02, 2019 1:03 am
Forum: Balancing Chemical Reactions
Topic: Why do we balance chemical equations?
Replies: 13
Views: 530

Re: Why do we balance chemical equations?

According to the law of conservation of mass, during a chemical reaction, mass is neither created or destroyed so the equation must be balanced in order to follow this law.
by Joanne Lee 1I
Wed Oct 02, 2019 1:02 am
Forum: SI Units, Unit Conversions
Topic: Textbook
Replies: 7
Views: 64

Re: Textbook

I think you can leave the textbook at home since often times during lecture we are taking notes off of Dr. Lavelle's powerpoints. The textbook is probably just helpful for the homework or for supplementary knowledge if something in the lecture was confusing for you.
by Joanne Lee 1I
Wed Oct 02, 2019 1:01 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Avogadro's Number [ENDORSED]
Replies: 12
Views: 118

Re: Avogadro's Number [ENDORSED]

If I am not mistaken, you use Avogadro's Number to find the number of atoms, molecules, or formula units when you are given the number of moles of any substance.
by Joanne Lee 1I
Wed Oct 02, 2019 12:58 am
Forum: Significant Figures
Topic: Rounding the elements
Replies: 12
Views: 90

Re: Rounding the elements

I personally round it to the hundredth place of the decimal place and it usually gets me the same answer as the answer in the solutions manual so that should work but I guess the safest option would be using all the values in the periodic table.

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