Search found 58 matches

by Hannah Rim 2D
Mon Dec 07, 2020 2:52 pm
Forum: Student Social/Study Group
Topic: Recorded Lectures
Replies: 9
Views: 79

Re: Recorded Lectures

It seems to be working on and off. Hopefully this problem gets fixed soon ):
by Hannah Rim 2D
Mon Dec 07, 2020 2:51 pm
Forum: Student Social/Study Group
Topic: Plans for Relaxing After Finals
Replies: 98
Views: 459

Re: Plans for Relaxing After Finals

I'm going to catch up on all the shows that I've been meaning to watch but didn't have the time to! I also want to spend more time sleeping and with my family (:
by Hannah Rim 2D
Mon Dec 07, 2020 2:46 pm
Forum: Quantum Numbers and The H-Atom
Topic: probabilty of finding e- in a location
Replies: 6
Views: 59

Re: probabilty of finding e- in a location

I don't think we will have to know how to calculate the exact probability of finding atoms in a region for the final. I think the focus will be on understanding conceptually through the shapes of orbitals. Hope this helps!
by Hannah Rim 2D
Mon Dec 07, 2020 2:39 pm
Forum: General Science Questions
Topic: Terminal Atom
Replies: 4
Views: 57

Re: Terminal Atom

Yes, you are correct. Terminal atoms are the atoms that surround the central atom. Hope this helps!
by Hannah Rim 2D
Mon Dec 07, 2020 2:36 pm
Forum: Student Social/Study Group
Topic: Calculating grade
Replies: 24
Views: 254

Re: Calculating grade

If we complete the sapling assignments by the due dates are we guaranteed the full 50 points for that portion of our grades? Yes we are! As long as you got 100% on the assignment and turned it in on time, you should get full marks. If you want to check, the grades for our sapling assignments are au...
by Hannah Rim 2D
Mon Dec 07, 2020 2:33 pm
Forum: Administrative Questions and Class Announcements
Topic: Unable to view the lectures
Replies: 12
Views: 123

Re: Unable to view the lectures

I had this problem the last midterm too and honestly, I'm not sure what the fix was. Sometimes it would work but sometimes it wouldn't. Hopefully this gets fixed soon!
by Hannah Rim 2D
Fri Dec 04, 2020 2:06 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acid strength and bond length
Replies: 11
Views: 88

Re: Acid strength and bond length

Weaker/ longer bonds are stronger acids because the molecule can dissociate more easily in water. In your example, HBr has a longer bond length than HCl. Thus, HBr is a stronger acid because it is weaker and will dissociate more in water. Hope this helps!
by Hannah Rim 2D
Fri Dec 04, 2020 2:01 am
Forum: Student Social/Study Group
Topic: How are you?
Replies: 117
Views: 788

Re: How are you?

Honestly, overwhelmed. On top of UCLA classes, I am working a job that I go to right after I finish my classes. I close almost everyday, so I come home at 10:30. I just always feel like I have absolutely no time for anything, and December is one of those months that keep me up all night. Scared for...
by Hannah Rim 2D
Fri Dec 04, 2020 1:47 am
Forum: Lewis Acids & Bases
Topic: 6 strong acids
Replies: 4
Views: 50

Re: 6 strong acids

Hi! The 6 strong acids listed in our textbook are HCl, HBr, HI, H2SO4, HNO3, and HClO4. Additionally, depending on the source, some consider HClO3 a strong acid as well. Since Dr. Lavelle only mentioned 6 strong acids, he likely counts HClO3 as a weak acid but I just wanted to include this one for f...
by Hannah Rim 2D
Fri Dec 04, 2020 12:17 am
Forum: General Science Questions
Topic: curve
Replies: 16
Views: 155

Re: curve

Based on what I've heard from previous students, he uses a straight scale with no curve. But I heard he doesn't downcurve at least!
by Hannah Rim 2D
Fri Dec 04, 2020 12:10 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Weak Acid Meaning
Replies: 3
Views: 32

Re: Weak Acid Meaning

Yes, you are correct! As the previous commenters have stated, weak acids do not dissociate completely in water. Thus, the bonds in weak acids are stronger/ harder to break apart than strong acids.
by Hannah Rim 2D
Fri Nov 27, 2020 12:44 am
Forum: Naming
Topic: Ethylene Diamine Tetra Acetate
Replies: 6
Views: 29

Re: Ethylene Diamine Tetra Acetate

Hi! For our final exam, we probably will have to know since we'll be going over naming soon. As of now, I don't think you need to stress about it since it's something we haven't learned yet. It might help to get a head start though (: Hope this helps!
by Hannah Rim 2D
Fri Nov 27, 2020 12:40 am
Forum: Student Social/Study Group
Topic: Winter 2021 Classes
Replies: 20
Views: 217

Re: Winter 2021 Classes

Hey! I also wanted to take Chem 14BL and LS30B at the same time but I noticed that the finals schedule overlapped with each other. Did you end up enrolling in both of these classes?
by Hannah Rim 2D
Fri Nov 27, 2020 12:37 am
Forum: General Science Questions
Topic: Grade Breakdown
Replies: 32
Views: 353

Re: Grade Breakdown

Does anyone know the minimum points we can lose to maintain an A or A-? Or is he curving the grades later? I've mostly heard that he uses a straight grading scale with no curves (490/500=A+, 465/500=A and so on) but I'm not entirely sure on this. The only thing I know for sure is that he doesn't do...
by Hannah Rim 2D
Fri Nov 27, 2020 12:24 am
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Chart
Replies: 18
Views: 104

Re: VSEPR Chart

I'm pretty sure that we'll have to memorize the entire chart (shapes + angles). Hope this helps!
by Hannah Rim 2D
Fri Nov 27, 2020 12:19 am
Forum: Hybridization
Topic: Sp3d or dsp3
Replies: 22
Views: 870

Re: Sp3d or dsp3

I personally have used sp3d my entire life but Dr. Lavelle seems to use dsp3 so I switched up my notation. Regardless, Dr. Lavelle said both are fine and essentially the same!
by Hannah Rim 2D
Sun Nov 22, 2020 3:38 am
Forum: Student Social/Study Group
Topic: Study Tips for Final Exam
Replies: 57
Views: 415

Re: Study Tips for Final Exam

I'm definitely going to review Dr.Lavelle's recommended textbook problems because they were super helpful for the midterms! I also plan on rereading the textbook and making condensed notes. I might rewatch Dr. Lavelle's lectures and the Organic Chemistry Tutor on youtube for the concepts I'm struggl...
by Hannah Rim 2D
Sun Nov 22, 2020 3:30 am
Forum: Formal Charge and Oxidation Numbers
Topic: Best Formal Charge Equations
Replies: 24
Views: 133

Re: Best Formal Charge Equations

Hey! I calculate formal charge by doing FC=valence electrons - (dots + lines/bonds). I like to count the dots individually and the lines (bonds) only count for when when doing formal charge.
by Hannah Rim 2D
Sun Nov 22, 2020 3:26 am
Forum: Lewis Structures
Topic: Sapling Hw #12
Replies: 3
Views: 45

Re: Sapling Hw #12

Yes, you're right! You have to first use the mass percentages to figure out the molecular formula. With whatever formula you find, you just need to draw the lewis structure out onto sapling.
by Hannah Rim 2D
Sun Nov 22, 2020 3:21 am
Forum: Ionic & Covalent Bonds
Topic: Radicals
Replies: 10
Views: 96

Re: Radicals

I think you're right and it's just a textbook error. If there are an uneven amount of electrons then it has to be a radical.
by Hannah Rim 2D
Sun Nov 22, 2020 3:20 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Ground State vs. Excited State
Replies: 6
Views: 76

Re: Ground State vs. Excited State

A ground state electron configuration will look exactly the way you expect it to look if you wrote out the configuration as you see it on the periodic table. If you see a configuration that seems to "skip" any numbers while filling up the orbitals. then it is in the excited state.
by Hannah Rim 2D
Sat Nov 14, 2020 12:44 pm
Forum: Trends in The Periodic Table
Topic: N 3- vs S 2-
Replies: 4
Views: 41

Re: N 3- vs S 2-

Hm thats a tricky question that I was wondering about too but I think Sulfur 2- would have a larger atomic radius. As previous commenters have stated, shielding is present but not significant enough to cause Sulfur's atomic radius to be smaller than Nitrogen.
by Hannah Rim 2D
Sat Nov 14, 2020 12:42 pm
Forum: Student Social/Study Group
Topic: Participation
Replies: 45
Views: 355

Re: Participation

On ccle, your points have been updated until week 4! If you received 20 points so far, that means you have been getting full credit for your posts. At this point in time, you should have at least 35 posts (i think) in order to continue receiving full credit.
by Hannah Rim 2D
Sat Nov 14, 2020 12:37 pm
Forum: Student Social/Study Group
Topic: Constants/Equations Sheet
Replies: 5
Views: 43

Re: Constants/Equations Sheet

Hello! So far the equation sheet hasn't been updated or any indication that it will be updated so I think we may have to memorize the exceptions, equations, and periodic trends.
by Hannah Rim 2D
Sat Nov 14, 2020 12:33 pm
Forum: Electronegativity
Topic: Periodic Table Trend
Replies: 37
Views: 389

Re: Periodic Table Trend

Both electronegativity and ionization energy increase as you go left to right and bottom to up. This is why Fluorine (F) is the most electronegative element
by Hannah Rim 2D
Sat Nov 14, 2020 12:28 pm
Forum: Lewis Structures
Topic: Polyatomic Ions
Replies: 2
Views: 15

Re: Polyatomic Ions

Dr. Lavelle hasn't explicitly told us that we need to memorize polyatomic ions for the midterm so I think it's safe to say we don't need to. However, I think it would still be really helpful to memorize the common polyatomic ions such as nitrate, carbonate, etc.
by Hannah Rim 2D
Thu Nov 05, 2020 4:40 pm
Forum: *Shrodinger Equation
Topic: Midterm Scores
Replies: 30
Views: 336

Re: Midterm Scores

I think that the partial points were to be given in questions that had multiple parts (i.e. questions that are divided into parts a, b, c, etc.) but I don't remember any of the questions on the midterm being like that so I doubt that we will get partial credit for this midterm. I could be wrong tho...
by Hannah Rim 2D
Thu Nov 05, 2020 4:36 pm
Forum: Administrative Questions and Class Announcements
Topic: Reviewing Answers for Midterm 1
Replies: 13
Views: 133

Re: Reviewing Answers for Midterm 1

Hi! I think he said that he will be reviewing commonly missed questions from midterm 1 and midterm 2 for a final exam review. As of now, I am not sure if we will be able to see our full midterm exam anytime soon.
by Hannah Rim 2D
Thu Nov 05, 2020 4:33 pm
Forum: Trends in The Periodic Table
Topic: Nuclear Charge
Replies: 7
Views: 39

Re: Nuclear Charge

Yes, you are correct! Nuclear charge is the ability of protons to be able to attract electrons. Adding onto what Anna said, as nuclear charge increases, atomic radius decreases. This is because a higher nuclear charge attracts the electrons in closer, ultimately resulting in a smaller radius.
by Hannah Rim 2D
Thu Nov 05, 2020 4:27 pm
Forum: Properties of Light
Topic: Wavelength
Replies: 26
Views: 184

Re: Wavelength

Wavelength is usually converted to m as the default. However, if the problem is asking for a different unit of measure then we would have to convert our answer.
by Hannah Rim 2D
Thu Nov 05, 2020 4:16 pm
Forum: Trends in The Periodic Table
Topic: memorizing trends
Replies: 14
Views: 57

Re: memorizing trends

Electronegativity, electron affinity, and ionization energy tends to increase as you go from left to right and down to up. The atomic radii does the opposite as you go from left to right and down to up. I don't really have a great way to memorize the trends but all of trends are related and you can ...
by Hannah Rim 2D
Thu Nov 05, 2020 4:06 pm
Forum: Student Social/Study Group
Topic: Studying Tips
Replies: 23
Views: 159

Re: Studying Tips

The textbook problems were definitely super helpful for getting the basics down! The UA worksheets and sapling problems tend to be a bit harder and more complex. For this reason, I usually start out with doing textbook problems and then UA/sapling problems afterwards. I also like to make a page or s...
by Hannah Rim 2D
Wed Oct 28, 2020 4:56 pm
Forum: Properties of Light
Topic: UA Workshop Question
Replies: 4
Views: 68

Re: UA Workshop Question

Hey! I was super confused on this problem earlier today too. Regarding the 250 nm, you convert that wavelength to m to get 2.5*10^-7 m. With this conversion, we can use the equation E=hc/(lambda) and get the amount of energy per photon. The energy should be 7.95*10^-19 J/photon I believe. Since we'...
by Hannah Rim 2D
Wed Oct 28, 2020 3:40 pm
Forum: Photoelectric Effect
Topic: Energy of photon
Replies: 5
Views: 60

Re: Energy of photon

Yes, you are correct; Ep is Joules/photon. If you want to convert this to the unit, joules/mol, you can multiply the quantity by Avogadros number (6.022*10^23). This conversion works because there are about 6.022*10^23 photons in a mol. With dimensional analysis, you can cancel out the photons to ge...
by Hannah Rim 2D
Wed Oct 28, 2020 3:31 pm
Forum: Einstein Equation
Topic: Sapling HW #6
Replies: 4
Views: 84

Re: Sapling HW #6

Hi! For this problem, you need to divide the amount the total energy, 6.07×10−7 J by the answer you got in the previous question, 4.32×10^−19 J/photon. It may be clearer if you think of this through dimensional analysis. Since your unit for the total energy is in joules, if you multiply 1 photon/4.3...
by Hannah Rim 2D
Wed Oct 28, 2020 3:21 pm
Forum: Properties of Light
Topic: Which model of light is atomic spectroscopy?
Replies: 8
Views: 96

Re: Which model of light is atomic spectroscopy?

Hi! I am pretty sure that it represents the particle model of light. Atomic spectroscopy shows us that an atom absorbs/emits wavelengths only if it matches a specific amount. This proves to us that the energy of photons are quantized instead of being constant. For this reason plus the ones that prev...
by Hannah Rim 2D
Wed Oct 28, 2020 3:11 pm
Forum: Limiting Reactant Calculations
Topic: Textbook Fund. Problem M11
Replies: 2
Views: 42

Re: Textbook Fund. Problem M11

Hi! The amount of O2 they use is actually the excess amount of O2 that wasn't used up in the first reaction. To get the excess amount, find out the amount of O2 that was used up in the reaction. You can solve this through stoichiometry. Afterwards, subtract the amount that was reacted from the amoun...
by Hannah Rim 2D
Wed Oct 28, 2020 3:04 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation question (sapling hw2 #12)
Replies: 3
Views: 49

Re: Rydberg Equation question (sapling hw2 #12)

In general, change is represented as (final - initial)! Since the electron moved from n=3 to n=1, the "final" would be n=1because it is the final position the electron ended up. Likewise, n=3 would be the "initial" since that is where the electron started off at. Thus, n1 would b...
by Hannah Rim 2D
Wed Oct 28, 2020 2:58 pm
Forum: Properties of Light
Topic: UA Workshop Question
Replies: 4
Views: 68

Re: UA Workshop Question

Hey! I was super confused on this problem earlier today too. Regarding the 250 nm, you convert that wavelength to m to get 2.5*10^-7 m. With this conversion, we can use the equation E=hc/(lambda) and get the amount of energy per photon. The energy should be 7.95*10^-19 J/photon I believe. Since we'v...
by Hannah Rim 2D
Sun Oct 25, 2020 7:22 pm
Forum: DeBroglie Equation
Topic: De Broglie's Equation vs C=wavelength(v)
Replies: 8
Views: 75

Re: De Broglie's Equation vs C=wavelength(v)

Though both equations use the variable v, they represent different things. The "v" in Debroglie's stands for velocity (used interchangeably with speed) while the "v" in lambda=c/v stands for frequency. Depending on what is given in the problem, you will use either DeBroglie's or ...
by Hannah Rim 2D
Sun Oct 25, 2020 7:16 pm
Forum: Administrative Questions and Class Announcements
Topic: midterm 1
Replies: 10
Views: 93

Re: midterm 1

Hi! To my knowledge no one knows how many questions there will be on the midterm. Some TA's have told their students that the midterm isn't going to be that long though.
by Hannah Rim 2D
Sun Oct 25, 2020 3:59 pm
Forum: DeBroglie Equation
Topic: Derivation of Equations on Midterm?
Replies: 17
Views: 99

Re: Derivation of Equations on Midterm?

Since it is multiple choice, I'm 99% sure that derivations of equations wouldn't be on it. We have only a short amount of time to take the test so I think the questions will be focused more on the applications of equations! I hope this helps (:
by Hannah Rim 2D
Sun Oct 25, 2020 3:50 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation Confusion
Replies: 3
Views: 49

Re: Rydberg Equation Confusion

Generally, change is final - intial. Thus, in the equation

1/lamda=R(1/n^1-1/n^2)

n^1 would be final and n^2 would be intial. Hope this helps!
by Hannah Rim 2D
Sun Oct 25, 2020 3:33 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg details
Replies: 3
Views: 38

Re: Heisenberg details

Hi Khoa! I was actually confused on this too. I think for the sake of simplification, we can just assume that speed and velocity will be the same. That's what I've been doing this section and I haven't had any problems with it so far.
by Hannah Rim 2D
Sun Oct 25, 2020 2:58 pm
Forum: Balancing Chemical Reactions
Topic: Tips for Complicated Chemical Reactions
Replies: 6
Views: 72

Re: Tips for Complicated Chemical Reactions

Hi Rajshree! I understand how you feel because I have the same problem haha. Kind of like with empirical formulas, if you look at the ratio of the stoichiometric coefficients in your end result, it should be the lowest ratio possible. If you find that all the coefficients are divisible by some numbe...
by Hannah Rim 2D
Fri Oct 23, 2020 1:36 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra Post-Module Assessment
Replies: 4
Views: 52

Re: Atomic Spectra Post-Module Assessment

The answer is B! The other comments explained it pretty well. To add on to what they've already said, if you use the Rydberg equation and c=(lambda)(v) to calculate the wavelength of radiation emitted during both transitions, you will find that the statement is true. I find conceptual problems to be...
by Hannah Rim 2D
Sun Oct 18, 2020 1:09 am
Forum: Student Social/Study Group
Topic: How are you studying?
Replies: 203
Views: 1298

Re: How are you studying?

Honestly, I'm struggling trying to keep up with everything as well. But everyone here gave great tips! Forcing myself to sit down and work at an allotted time really helped me get work done. The Audio-Visual Focus-Topics have been a very useful resource for me but I think the most important thing to...
by Hannah Rim 2D
Sun Oct 18, 2020 12:53 am
Forum: Significant Figures
Topic: Sig Figs and Constants on Exams
Replies: 9
Views: 104

Re: Sig Figs and Constants on Exams

Personally, I think it might be better to use the full length of the constant and only do sig figs at the end. I'm not sure what Dr. Lavelle prefers but I know collegeboard marked questions with premature rounding as wrong. I usually keep the calculations in my calculator and do sigfigs for only my ...
by Hannah Rim 2D
Sun Oct 18, 2020 12:43 am
Forum: General Science Questions
Topic: Kelvin
Replies: 8
Views: 61

Re: Kelvin

Yes, when using the unit "Kelvin," we leave out the degrees part. As someone previously stated, this is because Kelvin does not have the degrees symbol as it is an absolute scale.
by Hannah Rim 2D
Sun Oct 18, 2020 12:35 am
Forum: DeBroglie Equation
Topic: What causes a diffraction pattern?
Replies: 9
Views: 111

Re: What causes a diffraction pattern?

Yes, you are correct! It is called interference when two waves overlap and they produce a resultant wave. Furthermore, both constructive interference and destructive interference results in a diffraction pattern. Hope this helps (:
by Hannah Rim 2D
Fri Oct 16, 2020 9:05 pm
Forum: Properties of Light
Topic: Kinetic energy of photon
Replies: 3
Views: 53

Re: Kinetic energy of photon

Hi Yun Su! Similarly to what KKrivenko_3J said, the SI Base Units for a Joule is kg*m^2*s^-2. When you multiply mass with velocity squared, you get kinetic energy. The units for mass in this case is kg, while the units for velocity squared is m^2*s^-2. When calculating for kinetic energy, the units ...
by Hannah Rim 2D
Fri Oct 16, 2020 8:58 pm
Forum: Significant Figures
Topic: SIG FIGS
Replies: 13
Views: 112

Re: SIG FIGS

Yes, I was taught that the sig figs for your answer should match the amount of sig figs in the question. If there are multiple numbers with different sig figs in the problem, you should use the least amount of sig figs that were used in the problem.
by Hannah Rim 2D
Fri Oct 16, 2020 8:45 pm
Forum: Properties of Electrons
Topic: Sapling Homework
Replies: 4
Views: 51

Re: Sapling Homework

Yes! Since he is adding more questions to sapling, he is extending the due date so we have more time to do more problems. We have until Sunday midnight of Week 4 to finish the problems.
by Hannah Rim 2D
Sat Oct 10, 2020 2:42 am
Forum: Balancing Chemical Reactions
Topic: Sapling Wk1 Q10 Theoretical Yield and Actual Yield
Replies: 4
Views: 75

Re: Sapling Wk1 Q10 Theoretical Yield and Actual Yield

You don't need to balance the equation in this case because it is already balanced! When you write out the full chemical equation you can find that everything is a 1:1 mole ratio. I talked to my TA about this problem though and she said not to sweat too much on the ochem stuff. This problem was a bi...
by Hannah Rim 2D
Sat Oct 10, 2020 2:15 am
Forum: SI Units, Unit Conversions
Topic: Mole notation
Replies: 7
Views: 69

Re: Mole notation

They're interchangeable! Personally, I like to use g/mol because it's easier to work with when doing dimensional analysis. Both are fine though; the negative exponent in mols automatically puts mols on the denominator.
by Hannah Rim 2D
Sat Oct 10, 2020 2:12 am
Forum: Administrative Questions and Class Announcements
Topic: Exam Regulations
Replies: 7
Views: 64

Re: Exam Regulations

I'm pretty sure that they will be closed book and proctored (:
by Hannah Rim 2D
Sat Oct 10, 2020 1:59 am
Forum: Balancing Chemical Reactions
Topic: Order of Balancing Rxns
Replies: 23
Views: 116

Re: Order of Balancing Rxns

Hey! When I took AP Chem in high school my teacher would write each element in a column. On the left side of the column she made tallies for the reactants and on the right side she made tallies for the products. Kinda like this: I C I II H II III O III Honestly, this method might not be that efficie...
by Hannah Rim 2D
Mon Oct 05, 2020 9:40 pm
Forum: Limiting Reactant Calculations
Topic: M7 (Limiting Reactant Fundamental Exercise)
Replies: 3
Views: 58

Re: M7 (Limiting Reactant Fundamental Exercise)

Hi! Yes, I'm pretty sure that we will have to know how to write out full chemical equations using just the periodic table. I personally solve it this way: In this word problem, the question states that solid boron can be extracted from solid boron oxide. Solid boron is just "B" and solid b...

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