Search found 42 matches

by Jonathan Banh 1G
Sun Nov 22, 2020 3:43 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability of anions
Replies: 4
Views: 28

Re: Polarizability of anions

N^{3-} is more polarizable than O^{2-} because it has a larger ionic radius than oxygen and thus, its electron cloud is more easily distorted. Remember that ionic radius follows the pattern of atomic radius, once you separate the cations and anions. Thus, since nitrogen is to the left of oxygen on ...
by Jonathan Banh 1G
Sun Nov 22, 2020 2:06 pm
Forum: Octet Exceptions
Topic: Expanded Octets
Replies: 11
Views: 45

Re: Expanded Octets

Expanded octets can include those past 10 electrons, meaning valence shells with 12 are valid. For example, take sulfur hexafluoride (SF6). If we draw out its Lewis structure, it becomes clear that S, the central atom, has an expanded octet of 12 electrons. I am not 100% sure about valence shells wi...
by Jonathan Banh 1G
Sun Nov 22, 2020 1:45 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: 24
Views: 57

Re: London Dispersion

London dispersion forces (LDFs) are always occurring between molecules. They rely upon the electron's typical behavior of randomness and thus are momentary differences in charge throughout the molecule that are the result of arbitrary movement. Electrons are always randomly moving, so this is why LD...
by Jonathan Banh 1G
Sun Nov 22, 2020 4:03 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Ground State vs. Excited State
Replies: 6
Views: 26

Re: Ground State vs. Excited State

Just in case, ground-state electron configuration refers to the typical electron configuration that would expect to see in atoms of elements while excited-state electron configuration refers to the electron configuration that is observed in them after additional energy is absorbed. Personally, I fin...
by Jonathan Banh 1G
Sun Nov 22, 2020 3:44 am
Forum: Bond Lengths & Energies
Topic: IMF vs. Intramolecular Forces
Replies: 7
Views: 50

Re: IMF vs. Intramolecular Forces

In the question that you referenced, I believe what they are asking about are the intramolecular forces. This is because they ask about the strength of the molecule, hinting that they are testing you on your knowledge of bond strength, not the interactions that exist between like molecules. What is ...
by Jonathan Banh 1G
Sun Nov 22, 2020 3:10 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration for Silver?
Replies: 8
Views: 37

Re: Electron Configuration for Silver?

The electron configuration for silver (Ag) is [Kr]4d^{10}5s^1 because an atom of an element is more stable (less energy) when an electron fills up the d-orbital to d^5 or d^{10} . Thus, an atom of silver prefers that one electron from the 5s-orbital be donated or passed down to the 4d-orbital to ach...
by Jonathan Banh 1G
Sun Nov 15, 2020 6:53 pm
Forum: Ionic & Covalent Bonds
Topic: Hydrogen Bonding
Replies: 13
Views: 39

Re: Hydrogen Bonding

H-N, H-O, and H-F bonds are typically associated with hydrogen bonding due to how there exists a great electronegativity difference between H and the respective atoms. Thus, H will tend to be slightly positive while N, O, and F will tend to be slightly negative. This relationship is what facilitates...
by Jonathan Banh 1G
Sun Nov 15, 2020 5:52 pm
Forum: Lewis Structures
Topic: Nitrate Ion Lewis Structure
Replies: 6
Views: 26

Re: Nitrate Ion Lewis Structure

If drawn correctly, you should have a Lewis structure where N is the central atom, with no additional lone pairs, two O atoms that have a single bond to N, each with 3 lone pairs, and one O atom with a double bond to N, leaving it with 2 lone pairs. Referring back to the formula for formal charge, i...
by Jonathan Banh 1G
Sun Nov 15, 2020 5:36 pm
Forum: Electronegativity
Topic: Sapling Question 13
Replies: 7
Views: 28

Re: Sapling Question 13

For this question, you must focus on how electronegativity plays a role in urea. Notice that N is more electronegative than H, thus N will be slightly negative while H will be slightly positive. Seeing how this is the case, that means that in water, the 4 H in urea can technically form hydrogen bond...
by Jonathan Banh 1G
Sun Nov 15, 2020 5:22 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic v. Covalent Bonding
Replies: 16
Views: 84

Re: Ionic v. Covalent Bonding

In terms of your example, you have to recognize the mechanism behind the formation of the bond. In ammonium chloride, the difference in charges between NH4+ and Cl- is what attracts the two substances to each other and causes them to ionically bond with each other. It is clear here that no sharing o...
by Jonathan Banh 1G
Sun Nov 15, 2020 4:40 pm
Forum: Lewis Structures
Topic: Lewis acids and Bases
Replies: 20
Views: 74

Re: Lewis acids and Bases

I think the most important distinction here is to determine whether a substance is more likely to act as an electron-pair acceptor or donor. If it acts as an electron-pair acceptor, you would consider it as a Lewis acid. On the other hand, if it acts an electron-pair donor, you would consider it as ...
by Jonathan Banh 1G
Sun Nov 15, 2020 3:47 am
Forum: Student Social/Study Group
Topic: Test Anxiety
Replies: 62
Views: 229

Re: Test Anxiety

You're definitely not alone on this! I tend to have really bad test anxiety, but recently I have been getting better at suppressing it. Before the exam, I like to take breaks from studying every now and then to keep my mental health in check. I feel that this is super important, yet often overlooked...
by Jonathan Banh 1G
Sun Nov 08, 2020 4:36 pm
Forum: Electronegativity
Topic: Electronegativity trend
Replies: 18
Views: 81

Re: Electronegativity trend

Just to be clear, electronegativity is defined as the strength of which an atom pulls electrons, mainly shared ones, towards it. The periodic trend associated with this concept is that it increases as you go up columns and across periods to the right, meaning the most electronegative atoms are found...
by Jonathan Banh 1G
Sun Nov 08, 2020 4:22 pm
Forum: Lewis Structures
Topic: Lone Pairs Question
Replies: 22
Views: 90

Re: Lone Pairs Question

Lone pairs are formally defined as pairs of valence electrons that do not partake in shared electron bonding (covalent bonds). If this still does not make sense, my personal recommendation is to think of them as isolated pairs of electrons in a sense, meaning the two dots that you typically see besi...
by Jonathan Banh 1G
Sun Nov 08, 2020 4:00 pm
Forum: Formal Charge and Oxidation Numbers
Topic: What do we use formal charges for?
Replies: 15
Views: 48

Re: What do we use formal charges for?

Formal charge is defined as the amount of charge associated with a specific atom in a molecule. This is easier to understand in the context of its usage, which is to attribute resonant structures with some degree of stability. Assuming there are multiple resonant structures, the one deemed the most ...
by Jonathan Banh 1G
Sun Nov 08, 2020 3:49 am
Forum: Ionic & Covalent Bonds
Topic: Atomic Radius
Replies: 38
Views: 143

Re: Atomic Radius

Atomic radius decreases as you go across a period (left to right) because of how electron shielding remains constant while effective nuclear charge increases with the addition of protons. As a result, this increase in protons causes the attraction between the nucleus and electron cloud to increase, ...
by Jonathan Banh 1G
Sun Nov 08, 2020 3:29 am
Forum: Determining Molecular Shape (VSEPR)
Topic: n, l, mi
Replies: 8
Views: 54

Re: n, l, mi

n is what's known as the principal quantum number and represents the shell level. More specifically, it is the number before orbitals, such as 4s^2 where n = 4. l is the angular momentum quantum number and describes the orbital shape that is being dealt with, and although is technically n-1, I belie...
by Jonathan Banh 1G
Sun Nov 08, 2020 2:05 am
Forum: Electronegativity
Topic: Electronegativity vs. Electron Affinity
Replies: 8
Views: 34

Re: Electronegativity vs. Electron Affinity

Although they may seem the same because they share the same periodic trends (both increase as you move to the right across periods and up columns), a distinct difference does exist between the two concepts. Electronegativity refers to the attractive strength of which an atom (of an element) is capab...
by Jonathan Banh 1G
Sun Nov 01, 2020 1:58 pm
Forum: *Shrodinger Equation
Topic: For Ms (spin up, spin down)
Replies: 6
Views: 62

Re: For Ms (spin up, spin down)

I believe that the only values for the spin quantum number are m_s=\pm \frac{1}{2} . When determining the value for m_s , this is denoted by the arrows in the orbitals, where if they are pointing upwards, the spin is 1/2 while if they are pointing downwards, the spin is -1/2. On a side note, it is i...
by Jonathan Banh 1G
Sun Nov 01, 2020 1:40 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Sapling #24
Replies: 16
Views: 67

Re: Sapling #24

For this problem, you need to recognize that the ends of the waves must be on opposing sides of each other, meaning if the left side of the wave finishes above the line, then the right side must finish below and vice versa. The reason behind this is so that electron orbit will be comprised of only w...
by Jonathan Banh 1G
Sun Nov 01, 2020 5:28 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Shorthand Electron Configurations
Replies: 6
Views: 41

Re: Shorthand Electron Configurations

The shorthand method of writing electron configuration involves using noble gas notation for simplification, meaning replacing orbitals with the most recent preceding noble gas's known electron configuration. For example, [Ne] represents 1s^22s^22p^6 . Thus, we could use this to write sodium's elect...
by Jonathan Banh 1G
Sun Nov 01, 2020 4:49 am
Forum: Trends in The Periodic Table
Topic: Atomic Radius
Replies: 30
Views: 334

Re: Atomic Radius

The general periodic table trend for atomic radius is that it decreases as you go across a period (left to right), and increases going down a column. The reason behind the decrease in atomic radius from left to right is due to how the addition of protons, meaning the increase in atomic number, cause...
by Jonathan Banh 1G
Sun Nov 01, 2020 4:27 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Ground State Electron Configuration
Replies: 4
Views: 27

Re: Ground State Electron Configuration

For starters, the ground state electron configuration references when an atom is not energized, meaning it has no excess or additional energy. On the flipside, the excited state electron configuration illustrates when an atom is energized, meaning it possesses extra energy. Thus, with this input of ...
by Jonathan Banh 1G
Sun Nov 01, 2020 4:09 am
Forum: Properties of Light
Topic: Is c always the speed of light?
Replies: 70
Views: 236

Re: Is c always the speed of light?

In reference to the equation E=\frac{hc}{\lambda } , the variable c should always be representative of the speed of light. The speed of light, c, is generally approximated to 3.00*10^8 m/s, however, more accurately is 2.99792*10^8 m/s. In terms of other cases where c is a considered a different vari...
by Jonathan Banh 1G
Sun Oct 25, 2020 5:18 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: h/4pi
Replies: 7
Views: 60

Re: h/4pi

I believe \frac{h}{4\pi} is written out for both convenience and accuracy. Since both Planck's constant and π are constants, there is not really a need to create another constant from them, instead just using our known values of constants instead. Also, like others said, it is much easier to typing ...
by Jonathan Banh 1G
Sun Oct 25, 2020 5:00 pm
Forum: Properties of Electrons
Topic: intensity vs energy
Replies: 25
Views: 128

Re: intensity vs energy

This statement should be false. An increase in intensity implies an increase in the overall amount of photons present, not directly affecting the individual energy that each photon possesses. In order to increase the individual energy levels, you would need to alter the frequency.
by Jonathan Banh 1G
Sun Oct 25, 2020 4:16 am
Forum: Photoelectric Effect
Topic: Photoelectric Effect Problem
Replies: 6
Views: 61

Re: Photoelectric Effect Problem

I am not entirely 100% sure about my answer of 1.86*10^-9 m, but I am more than happy to share what I did. I started off by converting the provided 1.1 eV into joules and 810 nm to m in order to get the equivalent of 1.7622*10^-19 J and 8.10*10^-7 m, respectively. Then, I solved for the energy of th...
by Jonathan Banh 1G
Sun Oct 25, 2020 3:09 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Sampling 29
Replies: 3
Views: 31

Re: Sampling 29

First, you must recognize that aluminum (Al) has 13 electrons. While doing these types of problems, I would recommend referring to the "diagonal rule" for filling up orbitals, meaning 1s, 2s, 2p, 3s, etc. Remember that s-orbitals house 2 electrons while p-orbitals are capable of holding 6....
by Jonathan Banh 1G
Sun Oct 25, 2020 2:33 am
Forum: Student Social/Study Group
Topic: How to relax
Replies: 97
Views: 372

Re: How to relax

Personally, I love to listen to music, play games with friends, or talk to my family members when I am trying to relax. Especially with the midterm coming up, I definitely feel that this is becoming increasingly important, haha.
by Jonathan Banh 1G
Sun Oct 25, 2020 2:29 am
Forum: Administrative Questions and Class Announcements
Topic: Disabling question randomization in Sapling
Replies: 3
Views: 40

Re: Disabling question randomization in Sapling

I believe that Dr. Lavelle's email regarding Sapling question randomization was him making us aware to the presence of randomized questions in homework and the fact that he was working with Sapling tech support to disable it for clarity in regards to course material progression.
by Jonathan Banh 1G
Sun Oct 18, 2020 2:08 pm
Forum: Properties of Light
Topic: Frequency vs Wavelength
Replies: 22
Views: 132

Re: Frequency vs Wavelength

The fundamental understanding of the relationship between frequency and wavelength is that they are inversely related to each other, meaning that with a high frequency comes a short wavelength and vice versa. Going deeper into the topic, energy is also included in this as it is inversely related to ...
by Jonathan Banh 1G
Sun Oct 18, 2020 1:56 pm
Forum: Limiting Reactant Calculations
Topic: Difference between limiting reactant and limiting reagent?
Replies: 14
Views: 77

Re: Difference between limiting reactant and limiting reagent?

Although they are not exactly the same, just know that they are used interchangeably for the most part, so you don't have to worry about different methods of calculation. At the end of the day, the most important part to understand is that they are specifying which chemical is restricting or reducin...
by Jonathan Banh 1G
Sun Oct 18, 2020 3:22 am
Forum: Molarity, Solutions, Dilutions
Topic: Photoelectric Effect
Replies: 6
Views: 103

Re: Photoelectric Effect

For starters, you must first understand the equation related to the photoelectric effect that can be used to solve for this problem which is KE (Kinetic Energy) = E_photon - E_threshold energy. Breaking it down, the individual formula for KE is (1/2)(m*v^2), where m represents mass and v is velocity...
by Jonathan Banh 1G
Sat Oct 17, 2020 9:12 pm
Forum: Properties of Light
Topic: Conversions of Units and Equations
Replies: 3
Views: 30

Re: Conversions of Units and Equations

I am not 100% sure, but I would assume that he would allow us to view the constants and equations sheet on his website during exams. Knowledge of most necessary conversions should be gained through repetition of homework problems, however, if there is an unknown conversion then the exam problem will...
by Jonathan Banh 1G
Sat Oct 17, 2020 7:56 pm
Forum: Einstein Equation
Topic: m vs nm
Replies: 66
Views: 353

Re: m vs nm

I believe that as long as your answer is still accurate, it can in either meters or nanometers, unless explicitly stated otherwise. My TA said the preferred version is for it to be in nanometers, but leaving it in meters is also acceptable. It just comes down to it looking nicer and concise when the...
by Jonathan Banh 1G
Sat Oct 17, 2020 7:44 pm
Forum: Significant Figures
Topic: Sig Figs and Constants on Exams
Replies: 9
Views: 79

Re: Sig Figs and Constants on Exams

I would recommend using the full length of the constants when applying them in calculations because it gives a sort of "buffer" of accuracy in your final answer. Sure, it may only be one or two numbers off, but I think it is always best to be as accurate as possible with your answers. Usin...
by Jonathan Banh 1G
Sat Oct 10, 2020 7:53 pm
Forum: Empirical & Molecular Formulas
Topic: Ratios for empircal formulas
Replies: 6
Views: 59

Re: Ratios for empircal formulas

When solving for the empirical formula, you actually divide, not multiply when you find all the moles of each element in a substance. To be more specific, you divide each amount of moles by the smallest number of moles present. For example, between 0.5 mole of element X, 1 mole of element Y, and 1 m...
by Jonathan Banh 1G
Sat Oct 10, 2020 7:09 pm
Forum: Limiting Reactant Calculations
Topic: Theoretical yield: confused
Replies: 8
Views: 90

Re: Theoretical yield: confused

To help clarify, the preliminary aspect of theoretical versus actual yield is that theoretical yield is the maximum, PERFECT amount of product that you can gain from a reaction while actual yield is the practical, REALISTIC amount of product gained from a reaction after legitimate experimentation in...
by Jonathan Banh 1G
Sat Oct 10, 2020 6:47 pm
Forum: Empirical & Molecular Formulas
Topic: Sapling Homework 1 Q#9
Replies: 21
Views: 246

Re: Sapling Homework 1 Q#9

Absolutely! That is the first step in solving the problem. Using the given molecular weight of CO2, you can find the amount of carbon present in the product (it is the only substance with carbon). You can start by converting it to moles of CO2 instead, and then use that to find how many moles of car...
by Jonathan Banh 1G
Sat Oct 10, 2020 3:21 am
Forum: Administrative Questions and Class Announcements
Topic: Petition to Bring Music Back To Lectures [ENDORSED]
Replies: 34
Views: 527

Re: Petition to Bring Music Back To Lectures [ENDORSED]

Definitely want the music introductions back! Haha, maybe we can even convince Professor Lavelle to throw in a little dancing to spice up the lectures! Who knows! But on a real note, the music really helps in creating an environment that makes it feel more like a normal classroom rather than just a ...
by Jonathan Banh 1G
Fri Oct 09, 2020 7:43 pm
Forum: SI Units, Unit Conversions
Topic: Sapling Week 1 HW_problem #10
Replies: 8
Views: 102

Re: Sapling Week 1 HW_problem #10

I do not believe that your theoretical yield is incorrect, which is already a great step in the right direction. Just as a heads up, I did experience some issues where Sapling rounded down the solution for the theoretical yield instead of up. This will undoubtedly affect your percent yield if it is ...
by Jonathan Banh 1G
Fri Oct 09, 2020 2:36 pm
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student - Part II [ENDORSED]
Replies: 188
Views: 14326

Re: Advice from a Medical Student - Part II [ENDORSED]

Wow, honestly such an inspiring and interesting story to read. It's not very often that you get access to a "behind-the-scenes" look into the world of medical school, so thank you so much for choosing to share and consistently update your story! I would be lying if I said that the journey ...

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