Search found 36 matches

by Ashley Fang 3J
Mon Nov 11, 2019 5:54 pm
Forum: Student Social/Study Group
Topic: Chem 14B
Replies: 8
Views: 21

Re: Chem 14B

I'm taking chem 14B as well next quarter!
But I heard 14BL is better taken with 14C or after 14C if possible because of the level of knowledge you're expected to know.
by Ashley Fang 3J
Mon Nov 11, 2019 5:48 pm
Forum: Dipole Moments
Topic: Dipole Moment
Replies: 6
Views: 20

Re: Dipole Moment

To add to that, the arrow always points to the lowercase delta negative sign, and a line strikes through the arrow at the lowercase delta positive sign (making a cross or a "+" to help you remember it)
by Ashley Fang 3J
Mon Nov 11, 2019 5:30 pm
Forum: Electronegativity
Topic: Formula for Difference
Replies: 6
Views: 14

Re: Formula for Difference

If anything, the electronegativity values will be given if on a test.
The trends are increasing as you go up a column and also to the right across a period.
by Ashley Fang 3J
Mon Nov 11, 2019 5:28 pm
Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
Topic: Bonds vs Shapes [ENDORSED]
Replies: 4
Views: 231

Re: Bonds vs Shapes [ENDORSED]

To add to that, the dipoles can get closer together due to the greater surface area in rod-shaped molecules than spherical-shaped molecules, thus increasing the intermolecular forces.
by Ashley Fang 3J
Mon Nov 11, 2019 5:24 pm
Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
Topic: Polarizability and States
Replies: 3
Views: 20

Re: Polarizability and States

The greater the molecular mass, the greater the electron cloud distortion and polarizability. London dispersion forces tend to be stronger between molecules that are easily polarized. Thus, with a higher intermolecular force, the melting point/boiling point will also tend to be higher because more e...
by Ashley Fang 3J
Tue Nov 05, 2019 12:03 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Why is it 4f14 if there are 15 elements in that row
Replies: 2
Views: 67

Re: Why is it 4f14 if there are 15 elements in that row

Lanthanum is actually the first element of the 5d orbital, cerium through lutetium would be part of the f block
by Ashley Fang 3J
Mon Nov 04, 2019 12:40 am
Forum: Electronegativity
Topic: Electronegativity Ex.
Replies: 2
Views: 19

Re: Electronegativity Ex.

HCl has a greater ionic character than HI because hydrogen and chlorine's electronegativity difference is greater than that of hydrogen and iodine.
Remember that electronegativity increases right across a period and up a group!
by Ashley Fang 3J
Mon Nov 04, 2019 12:34 am
Forum: Lewis Structures
Topic: Drawing Lewis Structures
Replies: 3
Views: 21

Re: Drawing Lewis Structures

Naji Sarsam 4G wrote:2.) The charge of the central atom especially should either be 0 or negative (because it is the most electronegative atom); preferably 0 though


The central atom should be the least* electronegative atom
by Ashley Fang 3J
Mon Nov 04, 2019 12:27 am
Forum: Coordinate Covalent Bonds
Topic: Single, double, and triple bonds
Replies: 6
Views: 23

Re: Single, double, and triple bonds

The greater the electronegativity/electron affinity, the greater the pull on the electrons by the positively charged nucleus. Since fluorine is more electronegative than chlorine, the H-F single bond will be shorter than the H-Cl single bond. And as you increase the # of bonds (double, triple), you ...
by Ashley Fang 3J
Mon Nov 04, 2019 12:16 am
Forum: Lewis Structures
Topic: formal charge
Replies: 4
Views: 24

Re: formal charge

It can be calculated through FC = [# of valence electrons on atom] – [(# of lone pair electrons) + (# of shared electrons)/2]
by Ashley Fang 3J
Mon Oct 28, 2019 12:33 am
Forum: Bond Lengths & Energies
Topic: Chemical Bonds
Replies: 4
Views: 24

Re: Chemical Bonds

Picture yourself on top of a tree: you have high potential energy and are in a very unstable state.
Similarly, atoms don't like having a high potential energy; they'd rather create a bond and be stable at their lowest potential energy state.
by Ashley Fang 3J
Mon Oct 28, 2019 12:27 am
Forum: Lewis Structures
Topic: Choosing the central atom
Replies: 16
Views: 34

Re: Choosing the central atom

Ionization energy increases as you go up a column and to the right of a period. It's the energy required to remove an electron.
by Ashley Fang 3J
Mon Oct 28, 2019 12:23 am
Forum: Electronegativity
Topic: Fluorine's Electronegativity
Replies: 6
Views: 23

Re: Fluorine's Electronegativity

Adding to that, ignoring noble gases, fluorine also has little shielding effect since its electrons are close to the nucleus in the n=2 shell. Thus, the protons in the nucleus have a stronger pull on the electrons than in any other element.
by Ashley Fang 3J
Mon Oct 28, 2019 12:16 am
Forum: Electronegativity
Topic: isoelectronic atoms
Replies: 2
Views: 15

Re: isoelectronic atoms

On the contrary, I think that an atom that is isoelectronic with another atom of a fewer number of protons will attract more electrons, thus be more electronegative. Take for example N and F^2+. Although they both each have 7 electrons, fluorine will obviously attract more electrons because there is...
by Ashley Fang 3J
Mon Oct 28, 2019 12:09 am
Forum: Ionic & Covalent Bonds
Topic: Polarity
Replies: 6
Views: 24

Re: Polarity

Yes! An example of a polar covalent bond would be water (H2O), where most of the negative charge is from the oxygen on one side of the molecule and the positive charge of the hydrogen atoms is on the other side of the molecule. An example of a nonpolar covalent bond would be carbon dioxide (CO2), wh...
by Ashley Fang 3J
Mon Oct 21, 2019 12:22 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7569
Views: 1012015

Re: Post All Chemistry Jokes Here

.
by Ashley Fang 3J
Mon Oct 21, 2019 12:20 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7569
Views: 1012015

Re: Post All Chemistry Jokes Here

Hahahah
by Ashley Fang 3J
Mon Oct 21, 2019 12:15 am
Forum: Photoelectric Effect
Topic: Threshold Energy
Replies: 7
Views: 42

Re: Threshold Energy

I think that "ejected" just means that the electron is released from the atom. The detector that is used to measure the KE of the ejected electron has a slightly positive charge, thus causing it to move.
by Ashley Fang 3J
Mon Oct 21, 2019 12:09 am
Forum: Photoelectric Effect
Topic: Video module Test
Replies: 3
Views: 27

Re: Video module Test

Or, you could use the combined equations of E=hv and c=v(wavelength) to get (wavelength)=hc/E and solve for wavelength!
Hope that helps :)
by Ashley Fang 3J
Mon Oct 21, 2019 12:00 am
Forum: *Shrodinger Equation
Topic: derivation
Replies: 5
Views: 18

Re: derivation

Yupp, his constants and equations sheet can be found on his website or here

https://lavelle.chem.ucla.edu/wp-conten ... ations.pdf
by Ashley Fang 3J
Mon Oct 14, 2019 1:38 am
Forum: Student Social/Study Group
Topic: Study Group Fall 2019
Replies: 32
Views: 272

Re: Study Group Fall 2019

Count me in! :)
by Ashley Fang 3J
Mon Oct 14, 2019 1:34 am
Forum: Student Social/Study Group
Topic: Grades
Replies: 14
Views: 101

Re: Grades

KayleyW_3L wrote:In addition to wondering when the Test 1 grades will be posted, I am also curious whether there is partial credit on the exams?


I asked my TA and there's definitely partial credit given on exams if you show your work!
by Ashley Fang 3J
Mon Oct 14, 2019 1:32 am
Forum: Student Social/Study Group
Topic: Best Sessions
Replies: 12
Views: 49

Re: Best Sessions

Generally in step-up sessions, what's the usual TA to student ratio and about how much time do they spend with each student trying to understand the concepts?
by Ashley Fang 3J
Mon Oct 14, 2019 1:28 am
Forum: Student Social/Study Group
Topic: Textbook Readings
Replies: 4
Views: 28

Textbook Readings

Do you guys find the textbook readings to be more helpful for studying or other resources such as videos/lectures? I'm asking because I don't know if I'm missing any important information that's covered in the textbook that's not covered in Dr. Lavelle's videos or lectures. I feel like what tends to...
by Ashley Fang 3J
Mon Oct 14, 2019 1:15 am
Forum: Balancing Chemical Reactions
Topic: H 1
Replies: 6
Views: 82

Re: H 1

Another tip is to generally start out balancing the element that shows up the least often in the equation and then work from there, eventually getting to elements in diatomic molecules such as H2 or O2 that stand alone and are easy to balance by themselves (just add a coefficient in front)
by Ashley Fang 3J
Mon Oct 07, 2019 9:01 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7569
Views: 1012015

Re: Post All Chemistry Jokes Here

Hohoho
by Ashley Fang 3J
Mon Oct 07, 2019 9:01 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7569
Views: 1012015

Re: Post All Chemistry Jokes Here

Yes, I am positive!
by Ashley Fang 3J
Mon Oct 07, 2019 9:00 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7569
Views: 1012015

Re: Post All Chemistry Jokes Here

The one true bro
by Ashley Fang 3J
Mon Oct 07, 2019 8:57 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7569
Views: 1012015

Re: Post All Chemistry Jokes Here

Chemistry jokes are sodium funny!
I slapped my neon that one!
by Ashley Fang 3J
Mon Oct 07, 2019 8:30 pm
Forum: Ideal Gases
Topic: Reading the textbook [ENDORSED]
Replies: 127
Views: 74903

Re: Reading the textbook [ENDORSED]

Personally I find that every time I read the textbook, I tend to fall asleep because it's just that long and boring, especially when you're new to the material. What I usually will do however is take notes of the summary and important formulas/equations. Once I have grasped the basic concepts, I wil...
by Ashley Fang 3J
Fri Oct 04, 2019 12:58 am
Forum: Properties of Light
Topic: Speed of Light
Replies: 41
Views: 742

Re: Speed of Light

Speed of light is a constant and will be given during tests/exams.
The link of the constants and equations sheet is on his website but I'll link it here!

https://lavelle.chem.ucla.edu/wp-conten ... ations.pdf
by Ashley Fang 3J
Fri Oct 04, 2019 12:54 am
Forum: Limiting Reactant Calculations
Topic: Reviewing High School Chem Tips
Replies: 10
Views: 50

Re: Reviewing High School Chem Tips

Honestly chemmybear has a lot of great resources for high school chemistry topics.
I also remember watching a lot of Bozeman videos, he explained the topics in a very easy-to-understand way.
Here are the links below!

http://chemmybear.com/
http://www.bozemanscience.com/ap-chemistry/
by Ashley Fang 3J
Fri Oct 04, 2019 12:47 am
Forum: Molarity, Solutions, Dilutions
Topic: Converting Before or After?
Replies: 10
Views: 47

Re: Converting Before or After?

Convert the units first if you're going to be canceling them out with other units. You want to make sure that like units cancel out like units. For example, you would not do 5kg x 1mol/18.02g, you would change the 5kg to 5000g first to make sure you're left with only moles when you cancel out the gr...
by Ashley Fang 3J
Fri Oct 04, 2019 12:35 am
Forum: SI Units, Unit Conversions
Topic: Etext Access for Chem Book
Replies: 3
Views: 42

Re: Etext Access for Chem Book

Hmm I'm not sure about your extext access issue in particular but if you want there's also a free pdf version you could download

https://drive.google.com/file/d/1QBq9rF ... p=drivesdk
by Ashley Fang 3J
Fri Oct 04, 2019 12:13 am
Forum: SI Units, Unit Conversions
Topic: Bond Length
Replies: 5
Views: 38

Re: Bond Length

I believe it's the distance between the nuclei of two bonded atoms in a molecule. It depends on a lot of factors and definitely varies from molecule to molecule. If the bond strength is very high, then typically you'd have a smaller bond length. If the bond strength is weak, then you'd have a longer...

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