Search found 65 matches

by Yu Jin Kwon 3L
Sat Jan 16, 2021 8:52 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook Problem 6E.3
Replies: 2
Views: 16

Re: Textbook Problem 6E.3

Just for clarification, the reason why the cut off is Ka < 10^-4 (rather than the usual < 10^-3) is because Dr. Lavelle wanted us to be extra careful when using 10^-3 as a cut off because something could be a very large number multiplied with 10^-3, which would make it closer to 10^-2 than 10^-4 :)!...
by Yu Jin Kwon 3L
Sat Jan 16, 2021 8:45 pm
Forum: Student Social/Study Group
Topic: Comfort Movies
Replies: 108
Views: 237

Re: Comfort Movies

I love this thread!!! My comfort movie is probably "The Incredibles" because I first watched it when I was so young that it always brings me back to those childhood memories LOL!! Also, this isn't a movie, but I reaLLY recommend the show "We Bare Bears" because it literally ALWAY...
by Yu Jin Kwon 3L
Sat Jan 16, 2021 8:34 pm
Forum: Student Social/Study Group
Topic: Chemistry Community Posts
Replies: 22
Views: 51

Re: Chemistry Community Posts

I would probably stick to 5 points per week because not only is this what (I believe) Dr. Lavelle requires us to actually do, but doing this can also help YOU understand topics better by asking and answering questions weekly! I feel like it's going to be much harder to try and cram/force a bunch of ...
by Yu Jin Kwon 3L
Sat Jan 16, 2021 8:30 pm
Forum: Student Social/Study Group
Topic: Best Workshops
Replies: 8
Views: 42

Re: Best Workshops

The reason I love the UA workshops so much is because of the large variety that we can choose from (especially if we can't make some due to time conflicts with lectures or discussions from another class)!! I definitely think all the UAs' workshops are extremely helpful, and the ones I was able to ma...
by Yu Jin Kwon 3L
Thu Jan 14, 2021 2:22 am
Forum: Administrative Questions and Class Announcements
Topic: Textbook problem answer key
Replies: 5
Views: 21

Re: Textbook problem answer key

Hi Jenny! Mine overlap a bit, and I don't believe there is a way to fix this because it's a pdf :( I think for the most part, though, the text that overlaps is not the main solution to the problem, so you can still see the answer. In addition, I feel like the overlaps (to the extent where it's impos...
by Yu Jin Kwon 3L
Mon Jan 04, 2021 5:43 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5J.13 textbook problem
Replies: 3
Views: 28

Re: 5J.13 textbook problem

Hi! So this is kinda unlike our other problems where we did ICE box because they give you the K at the different temperatures, meaning we can just directly compare the different K values at the different temperatures. In this case, you want to find which one is the larger K because that would mean i...
by Yu Jin Kwon 3L
Mon Jan 04, 2021 5:38 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Special Case where K changes despite Same Temperature?
Replies: 2
Views: 17

Special Case where K changes despite Same Temperature?

Hello! For textbook problem 5H.1, it asked "For the reaction N 2 (g) + 3H 2 (g) ⇌ 2NH 3 (g) at 400. K, K = 41. Find the value of K for each of the following reactions at the same temperature ." First of all, how can K change in the first place despite being in the same temperature? Also, f...
by Yu Jin Kwon 3L
Mon Jan 04, 2021 5:22 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: AVFT part 1B pre-assessment #24
Replies: 2
Views: 17

AVFT part 1B pre-assessment #24

Hello! For the Audio-Visual Focus Topic part 1B pre-module assessment, #24 asks “Are solvents included in equilibrium constant expressions,” and I said "Sometimes" because, in the textbook, it said that the concentration is sometimes so diluted that it’s considered pure, so that’s when it ...
by Yu Jin Kwon 3L
Mon Jan 04, 2021 5:16 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: AVFT part 1A pre-assessment #26
Replies: 3
Views: 21

AVFT part 1A pre-assessment #26

Hello!! The question for the Audio-Visual Focus Topic part 1A pre-assessment #26 asked, “Why are equilibrium constants useful?” and I put that it was "one number that gives us information about the relative production rates of reactant and product," and it was marked as incorrect. Can some...
by Yu Jin Kwon 3L
Mon Jan 04, 2021 5:10 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5J.5 part d in Textbook Problems
Replies: 3
Views: 21

5J.5 part d in Textbook Problems

Hello! After checking the answer key for 5J.5, I found that the answer for part d of this problem was "no change (there is the same number of moles of gas on both sides of the equation)." However, there is clearly a difference in the number of moles (attached below), with the reactants hav...
by Yu Jin Kwon 3L
Sun Dec 13, 2020 1:02 am
Forum: Hybridization
Topic: Textbook problem 2.45 part b).
Replies: 5
Views: 129

Re: Textbook problem 2.45 part b).

That helps a lot! I think I pretty much get it now. However, I do have one follow up question: If The hybridization were something like sp^3, would the leftover orbital still be a p? In other words, since there are only 3 orbitals, even if hybridization were using all three, or even into a d orbita...
by Yu Jin Kwon 3L
Sat Dec 12, 2020 12:44 am
Forum: Bronsted Acids & Bases
Topic: Arrhenius acids and bases
Replies: 2
Views: 15

Re: Arrhenius acids and bases

I don't think we have to know Arrhenius acids and bases in-depth, especially because Dr. Lavelle didn't go over them. I think I remember from one of the UA review sessions that your definition would be enough in terms of just knowing what they are for the final. However, I think we don't really need...
by Yu Jin Kwon 3L
Sat Dec 12, 2020 12:43 am
Forum: Calculating the pH of Salt Solutions
Topic: 6C.17
Replies: 2
Views: 28

Re: 6C.17

I asked some UA's about this problem, and there really is no definite way we can approach this without knowing the Kb or Ka values (which it doesn't give us), so we probably won't be asked something like this without a Kb or Kb value. However, as Hazelle said, if you were to guess, you could say BrO...
by Yu Jin Kwon 3L
Sat Dec 12, 2020 12:41 am
Forum: Lewis Structures
Topic: Confused about Fe's (Iron) total valence electrons
Replies: 2
Views: 25

Re: Confused about Fe's (Iron) total valence electrons

I was also in the review session, and we talked about Chromium ([Ar] 3d^5 4s^1) in particular and how it has 6 valence electrons. First, I also thought you would only count the electrons in the final n level (4, so 1 valence electron), but you apparently count everything outside the bracket (5 elect...
by Yu Jin Kwon 3L
Sat Dec 12, 2020 12:34 am
Forum: Sigma & Pi Bonds
Topic: Pi bonds
Replies: 1
Views: 22

Re: Pi bonds

Hi Crystal! So I kinda answered someone's question that's similar to this, so I'm just gonna paste my answer and reword some things to make it make more sense for your question: So I'm going to talk about the double bonds in the 2nd/bottom attached picture because those bonds are the ones that have ...
by Yu Jin Kwon 3L
Sat Dec 12, 2020 12:26 am
Forum: Hybridization
Topic: Textbook problem 2.45 part b).
Replies: 5
Views: 129

Re: Textbook problem 2.45 part b).

So, you get π(O 2p, C 2p) because both O and C have an electron leftover in their p-orbital. Could you say more about why the electron is left over in the p-orbital? I'm having trouble understanding why pi bonds are always only p. Yeah for sure! So if you look at the hybridization of C and O in the...
by Yu Jin Kwon 3L
Fri Dec 04, 2020 12:19 am
Forum: Hybridization
Topic: Textbook problem 2.45 part b).
Replies: 5
Views: 129

Re: Textbook problem 2.45 part b).

Hi Anna! So part b is asking us to write the specific hybridization or composition of each lone pair or bond, so if you look at the structure of the H2C=CHCHO molecule, you'll see that there are 4 C-H bonds, 1 C=C bond, 1 C-C bond, and one C=O bond. We have to write the specific hybrid orbitals that...
by Yu Jin Kwon 3L
Thu Dec 03, 2020 11:59 pm
Forum: Hybridization
Topic: Difference between hybrid orbitals and hybridization
Replies: 5
Views: 689

Re: Difference between hybrid orbitals and hybridization

Just to add an additional question, what is the difference between hybridization schemes and hybridization? Or the difference between hybridization schemes and hybrid orbitals?
by Yu Jin Kwon 3L
Thu Dec 03, 2020 11:54 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: List of Ligands
Replies: 5
Views: 18

Re: List of Ligands

There's a nice list of ligands in our textbook :)! Table 9C.1! It might be helpful to memorize some of them (which may naturally come through practice as well).
by Yu Jin Kwon 3L
Thu Dec 03, 2020 11:52 pm
Forum: Naming
Topic: 9C 1 part c
Replies: 6
Views: 43

Re: 9C 1 part c

Hello! I'm not sure whether this is just my textbook or an issue in everyone's but in my 9C. 1 part c, the question read "CO(CN)5..." instead of Co. If someone could update me on whether that was just my textbook or if it's something I should alert the professor about, that would be great...
by Yu Jin Kwon 3L
Thu Dec 03, 2020 11:49 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Weak Acid Meaning
Replies: 3
Views: 31

Re: Weak Acid Meaning

I believe you're correct! If an acid is weak, it means it does not dissociate completely, meaning it's harder to break :)
by Yu Jin Kwon 3L
Sun Nov 29, 2020 1:15 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: formation of coordination compounds
Replies: 3
Views: 44

Re: formation of coordination compounds

That's a really good question! I feel like it has to do with H2O being really polar, which means that it can easily be broken if there are other ions around (and since salts are made up of cations and anions, water can easily be replaced in that sense). I'm not too sure if this is the most accurate ...
by Yu Jin Kwon 3L
Sun Nov 29, 2020 1:11 pm
Forum: Administrative Questions and Class Announcements
Topic: Uploading Screenshot
Replies: 1
Views: 19

Re: Uploading Screenshot

Hi Emilie! It shouldn't appear in the actual text box until after you click "Preview" or "Submit." You can also scroll down a bit until you see two tabs that say "Options" and "Attachments," then you can add files directly from your laptop instead of dragging....
by Yu Jin Kwon 3L
Sat Nov 28, 2020 11:28 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Double/Triple Bonds and Polarity
Replies: 8
Views: 60

Re: Double/Triple Bonds and Polarity

I'm not entirely sure if my logic is correct, but I think yes because double bonds mean that the distance between the (in the arsenate ion from your example) Oxygen atom (that is double bonded) and the As would be shorter, causing larger electron repulsion, making the molecule more polar (more uneve...
by Yu Jin Kwon 3L
Sat Nov 28, 2020 11:20 am
Forum: Ionic & Covalent Bonds
Topic: lone pairs -polar molecule
Replies: 10
Views: 92

Re: lone pairs -polar molecule

Hi Bethany! I would say no because if you have a diatomic molecule such as Br2, in which each Br atom has 3 lone pairs, but it is still a nonpolar molecule. Rather than just looking for lone pairs, I would say to look at the difference in electronegativity to determine polarity :)
by Yu Jin Kwon 3L
Sat Nov 28, 2020 11:17 am
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR identification of carbonate ion (CO3(2-))
Replies: 4
Views: 36

VSEPR identification of carbonate ion (CO3(2-))

Hello everyone! So in lecture 20, Dr. Lavelle talked about how the carbonate ion is identified as a trigonal planar, with all bond angles being 120 degrees. I've attached a picture of the lewis structure for carbonate ion, and as you can see, there is a double bond there. I understand that Dr. Lavel...
by Yu Jin Kwon 3L
Sat Nov 21, 2020 11:47 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration vs. Valence Electron Configuration
Replies: 2
Views: 42

Electron Configuration vs. Valence Electron Configuration

Hello! I just wanted to ask if there was a difference between electron configurations and valence electron configurations because I'm pretty sure there was a question on one of the textbook problems where it specifically asked for the valence electron configuration rather than just the electron conf...
by Yu Jin Kwon 3L
Sat Nov 21, 2020 11:43 am
Forum: Bond Lengths & Energies
Topic: kJ/mol for bond energy in Lecture #18
Replies: 3
Views: 67

kJ/mol for bond energy in Lecture #18

Hello!

From lecture #18, Dr. Lavelle talked about the energy of hydrogen bonds being -20kJ/mol, but I wanted to ask what 20 kJ was per mole of? The atoms that are being hydrogen bonded?

Thank you!
by Yu Jin Kwon 3L
Sat Nov 21, 2020 11:33 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Topic 2A excercise 3a
Replies: 4
Views: 45

Re: Topic 2A excercise 3a

Kayla and Rich explained it very well, and a method to check if your electron configuration is correct is to compare the number of electrons in your electron configuration with the electrons that your new element (S^(2-) is Ar, which has 18 electrons). So, [Ne] 3s^2 3p^6 has 18 electrons as well bec...
by Yu Jin Kwon 3L
Sat Nov 21, 2020 11:18 am
Forum: Sigma & Pi Bonds
Topic: Shape of sigma and pi bonds
Replies: 2
Views: 11

Re: Shape of sigma and pi bonds

Hello!

Just to add a visual aid, I've attached a picture that helped me visualize what these bonds may look like!

Hope this helps :)
by Yu Jin Kwon 3L
Sat Nov 21, 2020 11:12 am
Forum: Sigma & Pi Bonds
Topic: Sigma and Pi Bond Strength
Replies: 4
Views: 41

Re: Sigma and Pi Bond Strength

Sigma bonds are stronger than pi bonds because, for sigma bonds, a greater overlap between orbitals occurs. In addition, pi bonds only form in the addition to sigma bonds. Here is a nice picture demonstrating the overlap between orbitals and the relationships between sigma and pi bonds.
by Yu Jin Kwon 3L
Sat Nov 14, 2020 11:46 pm
Forum: Resonance Structures
Topic: Confusion on Potential Resonance Structure Diagram
Replies: 6
Views: 43

Confusion on Potential Resonance Structure Diagram

Hello! I remember seeing Lewis structures like the one I attached below on Dr. Lavelle's lectures, but I don't exactly remember why there are dashed lines and what the dashed lines represent. I feel like it had to do with resonance structures, which is why I am uploading this inquiry here. I also re...
by Yu Jin Kwon 3L
Sat Nov 14, 2020 11:30 pm
Forum: Lewis Structures
Topic: Valence Electrons vs. Formal Charge when making Lewis Structures
Replies: 4
Views: 14

Re: Valence Electrons vs. Formal Charge when making Lewis Structures

Wow, thank you all so much!! These were fantastic explanations :))
by Yu Jin Kwon 3L
Sat Nov 14, 2020 10:49 pm
Forum: Ionic & Covalent Bonds
Topic: Conceptual Question about Covalent Bonds
Replies: 1
Views: 23

Conceptual Question about Covalent Bonds

Hello everyone! I understand that covalent bonds occur when atoms share electrons, but the process in which Dr. Lavelle draws the covalent bonds (after initially connecting atoms with a single bond) when drawing the Lewis structures kind of confused me because he often took a lone pair (2 electrons)...
by Yu Jin Kwon 3L
Sat Nov 14, 2020 10:44 pm
Forum: Lewis Structures
Topic: Valence Electrons vs. Formal Charge when making Lewis Structures
Replies: 4
Views: 14

Valence Electrons vs. Formal Charge when making Lewis Structures

Hello! Something that I have a bit of difficulty with is determining what the valence electrons or formal charges are in the lewis structures. For example, in the lewis structure below (which does not have the formal charges on the elements), when looking at Nitrogen, do you say it has 8 valence ele...
by Yu Jin Kwon 3L
Sat Nov 14, 2020 9:30 pm
Forum: Lewis Structures
Topic: Sapling HW Q4
Replies: 3
Views: 48

Re: Sapling HW Q4

These are great responses! I get why elements would not want to have a lot of different charges, but what does "contributing" in this context exactly mean? How do charges "contribute" to a structure and how do charges "contribute" less or more?
by Yu Jin Kwon 3L
Sat Nov 14, 2020 8:10 pm
Forum: Quantum Numbers and The H-Atom
Topic: Exceptions for electron configuration
Replies: 3
Views: 38

Re: Exceptions for electron configuration

Katie said it perfectly! To add on, all the elements in group 6 and group 11 exhibit this exception. Although we might not have to know that for this midterm, it's nice to keep in the back of our minds to understand why Cr and Cu are exceptions :)
by Yu Jin Kwon 3L
Fri Nov 06, 2020 2:47 pm
Forum: Trends in The Periodic Table
Topic: Bond Length
Replies: 5
Views: 31

Re: Bond Length

I believe so! The stronger the electronegativity, the stronger the atoms pull the electrons, making the bond length shorter. And to add on a little bit more, shorter bond lengths are harder split (think of trying to snap a shorter pencil vs. a longer pencil), so bonds with elements that have stronge...
by Yu Jin Kwon 3L
Fri Nov 06, 2020 2:38 pm
Forum: Lewis Structures
Topic: Electron Configuration; Aufbau Principle
Replies: 5
Views: 56

Re: Electron Configuration; Aufbau Principle

Woah, this is so cool!!! Thank you so much :))
by Yu Jin Kwon 3L
Fri Nov 06, 2020 2:36 pm
Forum: Ionic & Covalent Bonds
Topic: Atomic Radius
Replies: 38
Views: 220

Re: Atomic Radius

Everyone above explained why the atomic radius decreases as you go right on the PT. To explain when electron-electron repulsion will occur and how that can impact the radius: when you go down the periodic table, you add more shells, meaning you have much more electrons to shield the positive charge ...
by Yu Jin Kwon 3L
Fri Nov 06, 2020 2:30 pm
Forum: Ionic & Covalent Bonds
Topic: Polarity
Replies: 9
Views: 89

Re: Polarity

Hi Jordi! I'm not entirely sure what you mean by ionic character, but polarity reflects how, in a covalent bond, when there are unequal electronegativities, the electrons are shared unequally (polar). If the elements have equal electronegativities, the electrons are shared equally and are called non...
by Yu Jin Kwon 3L
Fri Nov 06, 2020 2:24 pm
Forum: Ionic & Covalent Bonds
Topic: Classifying bonds
Replies: 3
Views: 35

Re: Classifying bonds

Hey Claire! According to someone in Chemistry Stack Exchange, "all ionic compounds and salts, and all salts are ionic compounds," and this was based on IUPAC's claim that a "salt" is "a chemical compound consisting of an assembly of cations and anions." So, I believe yo...
by Yu Jin Kwon 3L
Fri Nov 06, 2020 2:16 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Curve?
Replies: 12
Views: 118

Re: Midterm Curve?

I believe there are no curves for the overall class or any of the exams either, but I am not 100% sure, so someone please fact-check this :)
by Yu Jin Kwon 3L
Sun Nov 01, 2020 11:01 am
Forum: Balancing Chemical Reactions
Topic: Problem for UA Workshop 1
Replies: 2
Views: 47

Re: Problem for UA Workshop 1

Stuti explained it very well, but just to add on another piece of advice: I typically leave the molecules with fewer elements alone until close to the end, meaning I try to accommodate for the larger molecules first. This is because it's harder to manipulate the number of elements for the larger mol...
by Yu Jin Kwon 3L
Sat Oct 31, 2020 2:15 pm
Forum: Student Social/Study Group
Topic: Post Midterm Blues
Replies: 71
Views: 605

Re: Post Midterm Blues

It's okay you guys!!! I believe in all of you, and I bet you all did better than you think :D!! Also, we have a lot of opportunities to improve for this next midterm and final, such as the workshops, step-up sessions, and more! Don't give up, and stay positive :))
by Yu Jin Kwon 3L
Sat Oct 31, 2020 2:11 pm
Forum: Properties of Light
Topic: Different Wavelengths for Electromagnetic Radiation Spectrum
Replies: 3
Views: 32

Different Wavelengths for Electromagnetic Radiation Spectrum

Hi y'all! I found different answers for the wavelength distinctions of different electromagnetic radiations online and in the textbook. Do you all know which source we should rely on for the wavelengths, or does anyone have a solid range of wavelengths for each EM (radio, infrared, visible, UV, x-ra...
by Yu Jin Kwon 3L
Sat Oct 31, 2020 2:04 pm
Forum: Properties of Light
Topic: Is c always the speed of light?
Replies: 88
Views: 457

Re: Is c always the speed of light?

Yes, C is the speed of light (a constant). In addition, it's important to note that C is the speed of all the electromagnetic radiation that we've learned thus far (radio, infrared, visible, UV, x-ray, gamma-ray), meaning that the frequency or wavelength does not impact the speed of light; it is alw...
by Yu Jin Kwon 3L
Mon Oct 26, 2020 4:21 pm
Forum: DeBroglie Equation
Topic: Textbook 1B.23
Replies: 1
Views: 16

Textbook 1B.23

Hello everyone!! I sometimes get confused between using c = (lambda)v and lambda = h/p, especially for textbook question number 23. The question: What is the velocity of a neutron of wavelength 100. pm? I approached this problem initially by plugging in 100 times 10^-12 m into lambda and dividing c ...
by Yu Jin Kwon 3L
Sat Oct 24, 2020 6:30 pm
Forum: DeBroglie Equation
Topic: Advice for Correct Units for Midterm
Replies: 8
Views: 81

Advice for Correct Units for Midterm

Hello all! So something I realized that really helps me make sure I'm getting the correct answer is actually writing down the units as I fill in equations and such. This makes me really think about which units will cancel out, and it also helps me check to see if I'm using the correct numbers too. F...
by Yu Jin Kwon 3L
Sat Oct 24, 2020 6:23 pm
Forum: Properties of Light
Topic: De Brogile Sapling HW Problem help
Replies: 7
Views: 82

Re: De Brogile Sapling HW Problem help

Hi Heather! Sorry I saw your new question after I uploaded my response. I didn't have your exact question (mine dealt with a diatomic fluorine molecule), but it seems as though the mass of the diatomic nitrogen molecule should be 28.01g/mol or 28.01 x 10^-3 kg/mol. Then, I believe you do get 4.652 x...
by Yu Jin Kwon 3L
Sat Oct 24, 2020 6:18 pm
Forum: Properties of Light
Topic: De Brogile Sapling HW Problem help
Replies: 7
Views: 82

Re: De Brogile Sapling HW Problem help

Hi all! My Sapling question involved a diatomic fluorine molecule going 442.4 m/s. While I was looking back on this problem to try and help you, I realized that I first approached it using E = (0.5)mv^2, with mass being 37.996 x 10^-3 kg (mass of diatomic fluorine molecule) and velocity being 442.4 ...
by Yu Jin Kwon 3L
Sat Oct 24, 2020 5:58 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Confusion on Experimental Data Graph
Replies: 1
Views: 22

Confusion on Experimental Data Graph

Hello everyone! So I was reviewing the Experimental Data graph from Lecture #6, which shows the line spectrum of the Hydrogen atom. I realized that the way the wavelengths were written made the graph look like you were supposed to view the left side of the graph as the top part and the right side ...
by Yu Jin Kwon 3L
Sat Oct 24, 2020 5:49 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Question about the Delta X and what it stands for
Replies: 6
Views: 53

Question about the Delta X and what it stands for

Hi guys! So I've been noticing that different problems give us the (for example) radius of the atom and others give us the uncertainty in the position of the electron within that atom. So, I wanted to ask: is delta X the distance of the area (like the length of the radius of an atom) or the uncertai...
by Yu Jin Kwon 3L
Fri Oct 16, 2020 9:35 pm
Forum: Photoelectric Effect
Topic: Lecture 10/14 example problem
Replies: 3
Views: 24

Re: Lecture 10/14 example problem

Hi Sedge! I think your work is really good, and your answer is really close (5.502*10^-7 m = 550 nm, which is close to 551 nm). I tried your method on my calculator, and I kept all the values inside of my calculator, which gave me 5.506*10^-7. I think the only issue might have been keeping the whole...
by Yu Jin Kwon 3L
Fri Oct 16, 2020 9:27 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra Post-Assessment #39
Replies: 2
Views: 38

Re: Atomic Spectra Post-Assessment #39

Yep! The wording in the question specifically asked for energy emitted, so you have to put your value as a positive value, or else you'll be saying negative emitted, which is absorbed.
by Yu Jin Kwon 3L
Fri Oct 16, 2020 9:22 pm
Forum: Properties of Light
Topic: Energy Levels
Replies: 11
Views: 92

Re: Energy Levels

Hi David! Energy levels are the different electron shells an atom has, and when the electron gets excited by an incoming light/photon (and the energy of the photon matches the difference between an n-level and ground state for the electron, then the electron moves up the energy levels to the respect...
by Yu Jin Kwon 3L
Fri Oct 16, 2020 10:06 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Q#39 Atomic Spectra Post Assessment
Replies: 4
Views: 30

Re: Q#39 Atomic Spectra Post Assessment

Hi everyone! To answer Charlotte, it doesn't really matter which number you plug in for n1 or n2 because you're just trying to find the difference between 1/4 and 1/16. I personally like to imagine that the start of whatever the transition is is n1 (in this case, n = 4). This ends up giving me a neg...
by Yu Jin Kwon 3L
Thu Oct 15, 2020 9:47 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Terminology when Describing Atomic Spectroscopy and the Light that Hits the Electron
Replies: 2
Views: 37

Terminology when Describing Atomic Spectroscopy and the Light that Hits the Electron

Hello everyone! During Wednesday's lecture and the Atomic Spectra video module, Dr. Lavelle spoke of the different frequencies that the light/photon hits the electron with (for atomic spectroscopy), but in the line spectrum diagram for the H-atom, the different regions for the different lights (infr...
by Yu Jin Kwon 3L
Wed Oct 14, 2020 9:55 am
Forum: Photoelectric Effect
Topic: Photoelectric Effect
Replies: 5
Views: 80

Re: Photoelectric Effect

Hello all! I also had a question to add onto this, and you all mentioned it in your explanations, but this was the part I was the most confused about. So I understand that we are given the velocity of the ejected electron, but we aren't given the mass of the electron. I thought because electrons are...
by Yu Jin Kwon 3L
Tue Oct 06, 2020 10:51 pm
Forum: SI Units, Unit Conversions
Topic: E.17c
Replies: 2
Views: 18

Re: E.17c

Yep! By the way, there's an answer key if you go to the Table of Contents then go to Odd-Numbered Exercises :) It may take a while to load but I recommend opening up two tabs for the textbook (one on the Fundamentals questions and the other on the answer key so you can check after :D). Hope this hel...
by Yu Jin Kwon 3L
Tue Oct 06, 2020 10:35 pm
Forum: SI Units, Unit Conversions
Topic: E.9
Replies: 2
Views: 40

Re: E.9

Hi Angel! I was quite confused about what formula units were as well, but I realized it is the exchangeable units for Avogadro's number (6.022x10^23 formula units/mol). So you multiply 5.15g of MgSO4 with its molar mass, but flipped (so you can cancel out the grams: 1 mol MgSO4/246.51g), then you mu...
by Yu Jin Kwon 3L
Tue Oct 06, 2020 10:19 pm
Forum: Molarity, Solutions, Dilutions
Topic: Fundamentals G.25
Replies: 4
Views: 57

Re: Fundamentals G.25

I initially thought there would be no change because I attributed how when diluting a solution, moles of solute remain the same, so I assumed the number of the molecules of X would remain the same after diluting it. However, the answer key says otherwise, so can someone also touch on the difference ...
by Yu Jin Kwon 3L
Tue Oct 06, 2020 10:04 pm
Forum: Balancing Chemical Reactions
Topic: Week 1 Sapling #10 Balancing Reaction
Replies: 7
Views: 59

Re: Week 1 Sapling #10 Balancing Reaction

Thank you all so much for your clarification!! I'll ask my TA during my discussion time on Friday and let y'all know why it's okay to assume the 1:1 mole ratio :)
by Yu Jin Kwon 3L
Tue Oct 06, 2020 9:01 pm
Forum: Balancing Chemical Reactions
Topic: Week 1 Sapling #10 Balancing Reaction
Replies: 7
Views: 59

Week 1 Sapling #10 Balancing Reaction

Hello! I was completing the last problem from the Sapling problems, and I tried to balance the given chemical reaction C4H8O + C3H7Br + Mg -> C7H16O, and I got stuck because I realized there is no Br or Mg on the product side of the reaction. So, how can I go forward with solving this problem if the...
by Yu Jin Kwon 3L
Tue Oct 06, 2020 8:54 pm
Forum: Empirical & Molecular Formulas
Topic: M. 19 (writing the equation)
Replies: 5
Views: 47

Re: M. 19 (writing the equation)

Hello! This is a really great question and this relates to something I was wondering as well. Will we be expected to know exactly what the chemical formula constitutes of (in terms of elements) with just the name of the compound (for this example: caffeine) during exams or will the elements be given...

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