Search found 47 matches

by t_rasul3I
Sun Nov 29, 2020 10:00 pm
Forum: Student Social/Study Group
Topic: Studying From Home
Replies: 91
Views: 291

Re: Studying From Home

I am blessed to have a designated desk in my room so I lock myself in my room, hide my phone in a drawer, and grind. Sitting at a designated study space makes me feel like I'm productive even though I am not. Moreover having that space is nice for me because I often have my mom basically screaming o...
by t_rasul3I
Sun Nov 29, 2020 9:55 pm
Forum: Student Social/Study Group
Topic: Participation
Replies: 25
Views: 170

Re: Participation

I once emailed Dr.Lavelle about Chem Community and he verified that if you are missing a couple of points here or there from CC, you can still make up for those by the end of the quarter.
by t_rasul3I
Sun Nov 29, 2020 9:53 pm
Forum: Student Social/Study Group
Topic: Week 8/9 Thoughts/Worries
Replies: 41
Views: 121

Re: Week 8/9 Thoughts/Worries

I was so lazy in week 8 because of thanksgiving and all. But I did get some nice retail therapy in to treat myself for doing the bare minimum. *Sigh* I'm already exhausted from finals week and I haven't even done anything but think about it.
by t_rasul3I
Sun Nov 29, 2020 9:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: How to determine negative poles? (Week 8 Sapling Q10)
Replies: 9
Views: 19

Re: How to determine negative poles? (Week 8 Sapling Q10)

negative poles are toward the most electronegative regions. it's kind of similar to how negative formal charges like to stay with the most electronegative atoms
by t_rasul3I
Sun Nov 29, 2020 9:45 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: How do bonds affect shapes?
Replies: 11
Views: 32

Re: How do bonds affect shapes?

the type of bonds do not affect the shape of these models, only the strength of the bond. What does affect shape are the lone pairs and their repulsions.
by t_rasul3I
Sun Nov 29, 2020 9:44 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sapling #20 AsO43- polarity
Replies: 6
Views: 17

Re: Sapling #20 AsO43- polarity

Since its a resonance structure, all the bond lengths and charges will distribute in real life and so you will be left with even distributions of bonds and charges to form a tetrahedron shape. Moreover, since the elements bonding to the central atom are the same, you know it has dipole moments that ...
by t_rasul3I
Sun Nov 29, 2020 9:41 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sapling HW #17
Replies: 7
Views: 29

Re: Sapling HW #17

I think the one you might be missing is using a ring of a triangle to connect the carbons together. This should help you get that last resonance structure.
by t_rasul3I
Sun Nov 29, 2020 9:40 pm
Forum: Hybridization
Topic: Confused on hybridization conceptually
Replies: 9
Views: 35

Re: Confused on hybridization conceptually

Hybridization, as mentioned above, is the mixing of orbitals. To find the hybridization symbol (which is essentially what the homework asks for most of the time), count how many areas of electron density there is and divide it into orbitals. 1 area of electron density is s and 4 areas of electron de...
by t_rasul3I
Sun Nov 22, 2020 8:58 pm
Forum: Octet Exceptions
Topic: Where to place radicals
Replies: 5
Views: 56

Re: Where to place radicals

Hey David, Yea it's kind of weird because for the textbook problems, it seemed like formal charge wasn't what determined which atom has the unpaired electron. However, from what I've seen it seems like the most electronegative atom will want the full octet, so the less electronegative species will ...
by t_rasul3I
Sun Nov 22, 2020 8:54 pm
Forum: Biological Examples
Topic: Carbon monoxide poisoning
Replies: 3
Views: 116

Re: Carbon monoxide poisoning

the carbon atom has the negative formal charge so I think that's why iron binds to it. The same principle applies with CN or cyanide which is why both of these compounds are deadly.
by t_rasul3I
Sun Nov 22, 2020 8:48 pm
Forum: Student Social/Study Group
Topic: Finals!
Replies: 43
Views: 207

Re: Finals!

im not going to lie, but I forgot everything about debroglies wavelength or e=hv or stuff like that.
by t_rasul3I
Sun Nov 22, 2020 8:42 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: London Dispersion
Replies: 29
Views: 70

Re: London Dispersion

London dispersion forces are always present and in every molecule including non-polar forces. There are more dispersion forces in bigger molecules because there is more surface area essentially. Therefore, bigger molecules have higher boiling points.
by t_rasul3I
Sun Nov 22, 2020 8:36 pm
Forum: Student Social/Study Group
Topic: Grading Scale for Chem14A
Replies: 22
Views: 144

Re: Grading Scale for Chem14A

You would have to consider the points in the class. 100 points are from weekly homework stuff, 220 are from midterms and 180 is from the final. You can miss 50 points to get an A- (3.7) in the class and 35 points to get a A (4.0) in the class. Calculate all the points you have right now out of avail...
by t_rasul3I
Sun Nov 22, 2020 8:33 pm
Forum: Student Social/Study Group
Topic: Exercising Our Minds and Bodies
Replies: 92
Views: 269

Re: Exercising Our Minds and Bodies

I run about 5 miles a day. Ok so originally I started working out and running this January for the sole reason of getting ready for college and looking sNaTcHeD and literally no intentions of being healthy. It was literally for all the wrong reasons. But then I liked it eventually because exercising...
by t_rasul3I
Sun Nov 22, 2020 8:27 pm
Forum: Student Social/Study Group
Topic: Big Sad: Midterm 2
Replies: 74
Views: 466

Re: Big Sad: Midterm 2

I totally feel you. Smh I feel like I mastered most of the concepts but then when I take the tests, I make such silly errors and feel kind of bummed out since each point has so much worth in our grade. But we will get through this!!!!!
by t_rasul3I
Sun Nov 15, 2020 6:56 pm
Forum: Dipole Moments
Topic: Dipole or Ion
Replies: 4
Views: 23

Re: Dipole or Ion

Dipole forces are intermolecular forces (between different atoms) and ionic forces are intramolecular forces (between on atom).
by t_rasul3I
Sun Nov 15, 2020 6:52 pm
Forum: Coordinate Covalent Bonds
Topic: Group 13 Elements
Replies: 4
Views: 39

Re: Group 13 Elements

No there are definitely other Lewis acid/bases reactors like people have mentioned above but group 13 elements are kind of like a guarantee that they are involved in this acid base reactions.
by t_rasul3I
Sun Nov 15, 2020 6:50 pm
Forum: Coordinate Covalent Bonds
Topic: When do we use it
Replies: 9
Views: 52

Re: When do we use it

coordinate covalent bonds are when a lone element like F comes and donates both of their electrons to create covalent bond. Basically, the electrons are not shared and one of the compounds donates their two electrons to create a bond. This happens where there are partial positive and negative charges.
by t_rasul3I
Sun Nov 15, 2020 6:42 pm
Forum: Octet Exceptions
Topic: Identifying Radicals
Replies: 24
Views: 98

Re: Identifying Radicals

Hi Kaitlyn. You can identify radicals by normally drawing out a Lewis structure and assigning formal charges to find the lowest formal charge. An example is laughing gas or nitric oxide (NO) and seeing that the lowest formal charge is when N has a radical.
by t_rasul3I
Sun Nov 15, 2020 6:39 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Dipole-dipole vs Dipole-induced dipole
Replies: 5
Views: 17

Re: Dipole-dipole vs Dipole-induced dipole

Like the other posts have mentioned above, dipole dipole forces happen between two polar molecules because their charges are not distributed evenly and so one positive end of a molecule will bond to one negative molecule of another molecule. A dipole induced force means that one strong nearby force ...
by t_rasul3I
Sun Nov 15, 2020 1:02 pm
Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
Topic: Rod vs spherical shaped molecules
Replies: 10
Views: 261

Re: Rod vs spherical shaped molecules

rod structures have more surface area (because they are longer and stretched out) and so they will have more areas to bond whereas a spherical structure does not have as many areas to bond. As a result, 2 rod structures are more strongly held together than two spherical structures.
by t_rasul3I
Sun Nov 08, 2020 12:58 am
Forum: Octet Exceptions
Topic: Radicals
Replies: 7
Views: 43

Re: Radicals

Based on the lecture on Wednesday, I think the main point of talking about radical was to show that they are compounds with unpaired electrons in an unstable, reactive state and that there are compounds in real life (like Vitamin C) that minimize radicals.
by t_rasul3I
Sun Nov 08, 2020 12:54 am
Forum: Electronegativity
Topic: Atom size
Replies: 22
Views: 730

Re: Atom size

Electronegativity does not directly affect atom size but there is correlation. Typically cations are smaller and they have less electronegativity and anions are larger and they have less electronegativity. Anions are smaller because they have more e- (more electronegativity) and so they have a large...
by t_rasul3I
Sun Nov 08, 2020 12:49 am
Forum: Electronegativity
Topic: periodic table
Replies: 16
Views: 118

Re: periodic table

atomic radii increase down a group and decrease across a period. cations are typically smaller and anions are larger. Ionization energy decreases down a group and increases accross a period. Electron affinity increases across a period.
by t_rasul3I
Sun Nov 08, 2020 12:44 am
Forum: Lewis Structures
Topic: lewis structure
Replies: 10
Views: 62

Re: lewis structure

Another simplified way to calculate formal charge is to subtract the number of "things" (symbols) around the element of interest from the number of valence electrons. Its not a precise way and I recommend using Dr.Lavelle's method to ensure you know the reasoning behind the formal charge, ...
by t_rasul3I
Sun Nov 08, 2020 12:42 am
Forum: Resonance Structures
Topic: Resonance Lecture Question
Replies: 10
Views: 65

Re: Resonance Lecture Question

The L stands for the number of lone electrons, or dots on the Lewis Structure.
by t_rasul3I
Sun Nov 08, 2020 12:37 am
Forum: Resonance Structures
Topic: Electron spin
Replies: 12
Views: 42

Re: Electron spin

There is not really a way to determine if an electron has a plus or minus 1/2 spin. Its just a numerical representation of the Pauli Exclusion principle where two orbitals in the same orbital will have opposite spins.
by t_rasul3I
Thu Nov 05, 2020 11:28 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration States
Replies: 2
Views: 19

Re: Electron Configuration States

I believe it is applied to all the other subsequent shells!
by t_rasul3I
Sun Nov 01, 2020 8:26 pm
Forum: Trends in The Periodic Table
Topic: Tips for remembering
Replies: 14
Views: 51

Re: Tips for remembering

I just remember two things: the farther right it is on the periodic table, the smaller it is. And, the more protons there is to the electrons, the tighter and smaller the atom is.
by t_rasul3I
Sun Nov 01, 2020 8:24 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Ionic Radius
Replies: 6
Views: 51

Re: Ionic Radius

The ionic radius is the distance from the nucleus to the outermost electron. Because electrons orbit super fast, there is a little cloud around the nucleus. The farther away the electrons are from the nucleus, the bigger their "cloud".
by t_rasul3I
Sun Nov 01, 2020 8:21 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Textbook Exercise 1E.15
Replies: 6
Views: 40

Re: Textbook Exercise 1E.15

Ground state refers to having it at a state that is expected of the electrons, meaning they are not exited or anything. Moreover, just count the electrons given despite the configuration to determine the specific electron.
by t_rasul3I
Sun Nov 01, 2020 8:19 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: h vs. ħ?
Replies: 11
Views: 88

Re: h vs. ħ?

I understand that h bar is the same set up as h/4pi. But why do we have a complicated/different set up of the equation. Is there something it was derived from?
by t_rasul3I
Sun Nov 01, 2020 8:17 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Sapling 26
Replies: 8
Views: 62

Re: Sapling 26

Hi! I think you might not have converted your units and/or may have plugged your answer into the calculator incorrectly like the previous comments said. You set up the initial problem variables correctly though.
by t_rasul3I
Fri Oct 23, 2020 11:14 pm
Forum: *Particle in a Box
Topic: Midterm 1
Replies: 16
Views: 224

Re: Midterm 1

How does the particle in the box concept relate to what was on that lecture? I remember it was mentioned after the electron constructive and destructive phases.
by t_rasul3I
Fri Oct 23, 2020 11:12 pm
Forum: Properties of Light
Topic: Speed of light
Replies: 25
Views: 136

Re: Speed of light

I think for the midterm, since it is multiple choice, we can use either value to calculate because we should still get a very close answer to the correct answer.
by t_rasul3I
Fri Oct 23, 2020 11:10 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Showing our Work on the Midterm
Replies: 10
Views: 55

Re: Showing our Work on the Midterm

Yes we will be allowed to have scratch paper lol. Because I do not know how we would be able to do work without it.
by t_rasul3I
Fri Oct 23, 2020 11:08 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra Post-Module Assessment
Replies: 4
Views: 48

Re: Atomic Spectra Post-Module Assessment

"The transition from n = 4 to n = 2 emits radiation of longer wavelength than the transition from n = 5 to n = 1." is the correct answer because n = 4 to n = 2 emits less energy and less energy means longer wavelengths
by t_rasul3I
Fri Oct 23, 2020 11:07 pm
Forum: *Black Body Radiation
Topic: Understanding Black Body Radiation
Replies: 7
Views: 189

Re: Understanding Black Body Radiation

Black body radiation is essentially a "theoretical or model body which absorbs all radiation falling on it, reflecting or transmitting none back. it has something to do with temperature. it won't be covered on the midterm though I believe
by t_rasul3I
Fri Oct 16, 2020 12:40 pm
Forum: Einstein Equation
Topic: Equation Sheet
Replies: 15
Views: 121

Re: Equation Sheet

I think we kind of end up memorizing the equation sheet as we do the HW because there's only a handful of equations and constants.
by t_rasul3I
Fri Oct 16, 2020 12:38 pm
Forum: Properties of Electrons
Topic: energy levels
Replies: 4
Views: 64

Re: energy levels

In Dr.Lavelle's lecture, he mentioned some electrons only jump down to a few levels. This was seen in the hydrogen spectrum example where some electrons jumped all the way down to n=1 and some were at n=3
by t_rasul3I
Fri Oct 16, 2020 12:34 pm
Forum: Properties of Light
Topic: "Intensity"
Replies: 20
Views: 128

Re: "Intensity"

intensity is the amplitude of the wave. And even if you read the threshold with the proper intensity, one photon can only interact with one electron.
by t_rasul3I
Tue Oct 13, 2020 12:27 am
Forum: Limiting Reactant Calculations
Topic: Unit clarification
Replies: 3
Views: 41

Unit clarification

Problem L35 from textbook
What mass of iron, in kilograms, is needed to produce 2.50 t of NaBr? Note that these equations must first be balanced!


In this context, what does t mean?
by t_rasul3I
Tue Oct 13, 2020 12:23 am
Forum: Limiting Reactant Calculations
Topic: Sapling #10 Question [ENDORSED]
Replies: 4
Views: 71

Re: Sapling #10 Question [ENDORSED]

Do we need to learn how to decipher skeletal structures yet for the extent of this course? If so can someone link a video teaching it?
by t_rasul3I
Tue Oct 06, 2020 10:22 pm
Forum: Limiting Reactant Calculations
Topic: Sapling Homework Question 10
Replies: 16
Views: 224

Re: Sapling Homework Question 10

Do we need to understand the structure of molecules for this unit? Or will we be given the molecular formulas for problems like these?
by t_rasul3I
Tue Oct 06, 2020 1:44 pm
Forum: Empirical & Molecular Formulas
Topic: Sapling HW 9
Replies: 21
Views: 217

Re: Sapling HW 9

Why am I not getting a solid number to be divisible to find the empirical formula?
by t_rasul3I
Tue Oct 06, 2020 1:42 pm
Forum: Administrative Questions and Class Announcements
Topic: Step Up Sessions
Replies: 71
Views: 4402

Re: Step Up Sessions

Can I just join any UA peer learning session?
by t_rasul3I
Tue Oct 06, 2020 1:40 pm
Forum: SI Units, Unit Conversions
Topic: HELP WITH UNITS
Replies: 9
Views: 466

Re: HELP WITH UNITS

often times, if you do the dimensional analysis correctly and what not, the units should cancel itself and you should be left with the right unit in the end

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