Search found 50 matches

by Aydin Karatas 1A
Sun Nov 22, 2020 10:57 pm
Forum: Resonance Structures
Topic: Resonance Structures and Energy
Replies: 17
Views: 40

Re: Resonance Structures and Energy

Yes. Molecules want to be stable, so the resonance structure with the lowest energy will be preferred, for it is most stable.
by Aydin Karatas 1A
Sun Nov 22, 2020 10:43 pm
Forum: Ionic & Covalent Bonds
Topic: Ionization Energy
Replies: 19
Views: 65

Re: Ionization Energy

The outermost electrons will be the electrons that are most affected by another atom of high electronegativity. Since the inner electrons are shielding the outermost electrons for the full nuclear attraction of the nucleus, they are the easiest to remove.
by Aydin Karatas 1A
Sun Nov 22, 2020 10:40 pm
Forum: Trends in The Periodic Table
Topic: Exceptions to Trends in atomic radius
Replies: 1
Views: 10

Re: Exceptions to Trends in atomic radius

Looking at Dr. Lavelle's lecture from 10/28/2020, Oxygen (radius = 68 pm) does have a smaller radius than nitrogen (radius = 75 pm). However, there seems to be a couple of anomalies, such as Mg being larger than Na; Pb being larger than Tl. I don't think these exceptions are too big of a deal though...
by Aydin Karatas 1A
Sun Nov 22, 2020 10:31 pm
Forum: Lewis Structures
Topic: Expanded Valence
Replies: 11
Views: 40

Re: Expanded Valence

Expanded octets can occur in p-block elements in row 3 or below. This is because they have an unoccupied d-orbital that can accept more elections than the conventional octet rule. The most common ones you'll see are Sulfur, Phosphorus, and Chlorine.
by Aydin Karatas 1A
Sun Nov 22, 2020 10:25 pm
Forum: Bond Lengths & Energies
Topic: Boiling/Melting Point
Replies: 16
Views: 55

Re: Boiling/Melting Point

Intermolecular forces because it is the force between or "inter" molecules are responsible for holding materials together. Melting and boiling would cause these forces to weaken. Thus, we go from solid --> liquid --> gas.
by Aydin Karatas 1A
Sun Nov 15, 2020 7:09 pm
Forum: Octet Exceptions
Topic: Nitrogen
Replies: 4
Views: 29

Re: Nitrogen

Nitrogen will follow the octet rule. The main exceptions to keep in mind are H and He might only have 2 valence electrons; Li and Be might only have 4 valence electrons; B might only have 6 valence electrons; and P, S, and Cl can have octets larger than 8 due to having an empty d-orbital. Hope this ...
by Aydin Karatas 1A
Sun Nov 15, 2020 7:05 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sapling #20
Replies: 12
Views: 39

Re: Sapling #20

Hydrogen bonding does not occur between CH 3 CHO molecules because there are no positively charged hydrogens present. H must be covalently bonded to an N, O, or F in its own molecule to hydrogen bond with neighboring molecules. Dipole-dipole interactions are still possible since the oxygen is slight...
by Aydin Karatas 1A
Sun Nov 15, 2020 6:58 pm
Forum: Ionic & Covalent Bonds
Topic: Hydrogen Bonding
Replies: 13
Views: 37

Re: Hydrogen Bonding

On top of the fact that N, O, and F are very electronegative, which does cause them to have a slightly negative charge, for H bonding to occur, the H must also be slightly positive. H in methane can't hydrogen bond because there isn't a sufficient electrostatic difference between C and H, but H in w...
by Aydin Karatas 1A
Sun Nov 15, 2020 6:52 pm
Forum: Lewis Structures
Topic: Sapling weeks 5/6 Question 4
Replies: 6
Views: 40

Re: Sapling weeks 5/6 Question 4

The wording of this question also confused me at first. I'll use the carbon-nitrogen bond as an example to explain what this means. In this question, overwhelming, such as in "overwhelming C-N bond character", means that the size of the actual carbon-nitrogen bond in the question was much,...
by Aydin Karatas 1A
Sun Nov 15, 2020 6:46 pm
Forum: Coordinate Covalent Bonds
Topic: Covalent Bond Character
Replies: 7
Views: 30

Re: Covalent Bond Character

No ionic bond is purely ionic. There are some covalent characteristics present. This would include electron sharing and insolubility in water. Ionic compounds with highly polarizable anions (the electron cloud of the anion can be easily distorted) or cations that have high polarizing power (can more...
by Aydin Karatas 1A
Sun Nov 08, 2020 7:45 pm
Forum: Coordinate Covalent Bonds
Topic: Stability of Coordinate Covalent Bonds
Replies: 2
Views: 16

Re: Stability of Coordinate Covalent Bonds

Hello, When you said BF3, did you mean the BF3 molecule with a formal charge of 0? If so, then I believe it's actually more stable. I also believe it depends on which BF3 you're talking about to determine if it was less or more stable. BF3 also has another structure where it has a double bond conne...
by Aydin Karatas 1A
Sun Nov 08, 2020 7:31 pm
Forum: Coordinate Covalent Bonds
Topic: Stability of Coordinate Covalent Bonds
Replies: 2
Views: 16

Stability of Coordinate Covalent Bonds

I understand why Boron in BF3 can accommodate for one additional Fluoride but does this mean that Boron was less stable in BF3 because it was willing to take on another bond even though Boron has a formal charge of -1 in BF4?
by Aydin Karatas 1A
Sun Nov 08, 2020 7:25 pm
Forum: Electronegativity
Topic: Silver Halides
Replies: 5
Views: 14

Re: Silver Halides

This example was used just to show that ionic bonds can have covalent characteristics; as the anion became large in radius, it became less soluble in water, which is a covalent characteristic. Larger anions are highly polarizable, meaning their electron clouds can be more easily distorted. This mean...
by Aydin Karatas 1A
Sun Nov 08, 2020 7:20 pm
Forum: Resonance Structures
Topic: Electron spin
Replies: 12
Views: 42

Re: Electron spin

Unlike the other quantum numbers, ms was found experimentally, so there is no mathematical model to follow. If you see ms= +1/2 or -1/2, it is denoting a specific electron in a specific subshell.
by Aydin Karatas 1A
Sun Nov 08, 2020 7:15 pm
Forum: Ionic & Covalent Bonds
Topic: Sapling #2
Replies: 6
Views: 38

Re: Sapling #2

Under the "more" tab, you can use the charge icons to assign charges to atoms.
by Aydin Karatas 1A
Sun Nov 08, 2020 7:04 pm
Forum: Coordinate Covalent Bonds
Topic: Lewis Diagram
Replies: 4
Views: 35

Re: Lewis Diagram

From what I understood from his lecture, Dr. Lavelle said that when looking at a molecule with a coordinate covalent bond, there is no real way to distinguish it notationally from other bonds in the complex. It's context-dependent, meaning a diagram is used to show the before and after. If you wante...
by Aydin Karatas 1A
Sun Nov 08, 2020 6:54 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Cations and Anions
Replies: 4
Views: 15

Re: Cations and Anions

Cations refer to positively-charged ions, which means they lose electrons when being ionized. Anions refer to negatively-charged ions, which means they gained electrons when being ionized. Whether an atom wants to lose electrons to achieve a noble-gas configuration or gain atoms is based on its ioni...
by Aydin Karatas 1A
Sun Nov 08, 2020 6:36 pm
Forum: Student Social/Study Group
Topic: Chemistry Among Us
Replies: 31
Views: 174

Re: Chemistry Among Us

I'll take one for the team. Since everyone else is going to reactor, I'll go with green. If green does kill me, hopefully, through deduction of who did not go to reactor, the rest of y'all can figure out that green is the imposter. If not, rip me.
by Aydin Karatas 1A
Sun Nov 01, 2020 9:51 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Clarification on e- configuration exceptions
Replies: 2
Views: 17

Re: Clarification on e- configuration exceptions

The d5 and d10 configuration have lower energy than d4 and d9, respectively. Due to their symmetry in the d suborbital, d5 and d10 are more stable, and therefore an electron would fill these positions in rather than the next s-orbital.
by Aydin Karatas 1A
Sun Nov 01, 2020 9:44 pm
Forum: Student Social/Study Group
Topic: Halloween!!!
Replies: 54
Views: 219

Re: Halloween!!!

Hope everyone had a great Halloween yesterday! On Friday, my family did a little Halloween get-together and I dressed up in a Toothless onesie from How to Train your Dragon.
by Aydin Karatas 1A
Tue Oct 27, 2020 8:44 pm
Forum: Photoelectric Effect
Topic: Sapling Week 2,3,4 HW #4
Replies: 4
Views: 47

Re: Sapling Week 2,3,4 HW #4

In the first part of the question, you calculated for \phi , which is measured in J/photon . Divide \phi by the total energy of the burst of photons to get the number of photons. Since this question is dealing with the photoelectric effect, 1 photon energizes 1 electron. Therefore, the number of pho...
by Aydin Karatas 1A
Tue Oct 27, 2020 8:32 pm
Forum: Quantum Numbers and The H-Atom
Topic: Quantum numbers
Replies: 3
Views: 46

Re: Quantum numbers

m_{l} refers to different orientation that subshells can have (e.g. p_{x}, p_{y}, p_{z} ). When filling electrons in an electron configuration, there really is no designation for whether m_{l} =1 refers to p_{x} , p_{y} , or p_{z} . I would personally go x, y, then z but so long as you are consiste...
by Aydin Karatas 1A
Tue Oct 27, 2020 8:16 pm
Forum: SI Units, Unit Conversions
Topic: Temperature Conversions
Replies: 6
Views: 51

Re: Temperature Conversions

I would say it just generally a good thing to know the conversion between K and C°.

.

I don't really think there's any use to knowing the conversion between C° and F°, but the conversion is such.

.

¡sdןǝɥ sıɥʇ ǝdoH
by Aydin Karatas 1A
Tue Oct 27, 2020 8:02 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: S Orbitals and nodal planes
Replies: 5
Views: 56

Re: S Orbitals and nodal planes

Y e s , there is no point in the s-orbital where a nodal point exists, which means there is no point where e- ρ (electron density) = 0. In comparison to the p-, d-, and f-orbitals, s is the only orbital that lacks nodal points. Hope this helps. I might be way off on this but does the s-orbital have...
by Aydin Karatas 1A
Sun Oct 25, 2020 6:54 pm
Forum: Photoelectric Effect
Topic: Frequency and energy
Replies: 15
Views: 71

Re: Frequency and energy

Yes. In the equation E=h\nu , if you increase \nu , E will also increase. Conversely, wavelength and energy are inversely proportional as seen in the equation E=\frac{hc}{\lambda} . This makes sense since red light with a higher wavelength and lower frequency has less energy than blue light with a l...
by Aydin Karatas 1A
Sun Oct 25, 2020 6:41 pm
Forum: DeBroglie Equation
Topic: Determining KE from the De Broglie Equation
Replies: 2
Views: 25

Re: Determining KE from the De Broglie Equation

You would first start by isolating velocity in the De Broglie Equation. \lambda = \frac{h}{p}= \frac{h}{mv}\Rightarrow v=\frac{h}{m\lambda} Since we are given mass and wavelength, we can calculate velocity. Now that we know both velocity and mass, we can use the KE equation KE= \frac{1}{2}mv^{2} to ...
by Aydin Karatas 1A
Wed Oct 21, 2020 4:15 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: S Orbitals and nodal planes
Replies: 5
Views: 56

Re: S Orbitals and nodal planes

Yes, there is no point in the s-orbital where a nodal point exists, which means there is no point where e- ρ (electron density) = 0. In comparison to the p-, d-, and f-orbitals, s is the only orbital that lacks nodal points.

Hope this helps.
by Aydin Karatas 1A
Wed Oct 21, 2020 4:11 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Question about d orbitals from lecture 10/21/2020
Replies: 1
Views: 29

Re: Question about d orbitals from lecture 10/21/2020

The x 2 -y 2 denotes what plane the orbital is in. It is similar to d xy but d x 2 -y 2 is rotated about the z-axis 90°. The main thing to keep in mind is that these are mathematical models, so don't get too tripped up on the shape as Dr. Lavelle said today. https://qph.fs.quoracdn.net/main-qimg-c93...
by Aydin Karatas 1A
Wed Oct 21, 2020 4:01 pm
Forum: DeBroglie Equation
Topic: Rearranging De Broglie Equation
Replies: 17
Views: 105

Re: Rearranging De Broglie Equation

The De Broglie Equation states that λ=h/p, where p=mv. Therefore, we know that λ=h/mv. If λ and m are given and knowing that h is a constant, we can isolate for v with v=h/λm. The main thing to keep in mind with De Broglie conceptually is that small particles exhibit wave-like properties. Hope this ...
by Aydin Karatas 1A
Mon Oct 19, 2020 1:50 pm
Forum: Properties of Light
Topic: Photoelectric Experiment
Replies: 2
Views: 31

Re: Photoelectric Experiment

No, it will not result in electrons being ejected. In a previous lecture, Dr. Lavelle gave the analogy of runners trying to jump over a hurdle (the runners being the photons and jumping over the hurdle represent an electron being ejected). If none of the runners can jump over the hurdle, adding more...
by Aydin Karatas 1A
Mon Oct 19, 2020 1:46 pm
Forum: Photoelectric Effect
Topic: Photoelectric Experiment
Replies: 6
Views: 47

Re: Photoelectric Experiment

From a pure mathematical view, yes. This is because E = hv (regarding the energy of the photon hitting the sample) is equivalent to E = hc/(wavelength). C is the speed of light in a vacuum so the experiment must be done in a vacuum for this equivalency to be true. Conceptually, having the open atmos...
by Aydin Karatas 1A
Mon Oct 19, 2020 1:37 pm
Forum: Photoelectric Effect
Topic: What is equation is this ?
Replies: 11
Views: 69

Re: What is equation is this ?

c is the constant for the speed of light in a vacuum. It is used to relate the wavelength and frequency of EM waves with the equation c = (wavelength)v. In today's lecture, c is used in the derivation for De Broglie's equation: Since E = hc/(wavelength) and E = pc hc/(wavelength) = pc ---> wavelengt...
by Aydin Karatas 1A
Fri Oct 16, 2020 10:22 am
Forum: Properties of Electrons
Topic: Lyman vs. Balmer series
Replies: 20
Views: 142

Re: Lyman vs. Balmer series

For problems where the light is in the visible region (~700 nm - 400 nm), the Balmer Series is used. This means that for the Rydberg equation, n 1 =2. For problems where the light is in the ultraviolet region (~<400 nm), the Lyman Series is used. This means for the Rydberg equation, n 1 =1. Hope thi...
by Aydin Karatas 1A
Fri Oct 16, 2020 10:18 am
Forum: Photoelectric Effect
Topic: Using variables in our work
Replies: 8
Views: 43

Re: Using variables in our work

I don't see a problem with leaving the constant in letter form but I could be wrong on Dr. Lavelle's specific preference. I usually write out the constant in numerical form near/at the final step just because it gives me the opportunity to also write out what units the constant is measured in. One g...
by Aydin Karatas 1A
Wed Oct 14, 2020 11:15 am
Forum: Einstein Equation
Topic: m vs nm
Replies: 66
Views: 348

Re: m vs nm

If the question specifically asks for nm, then convert to nm. If the question does not specify anything, Dr. Lavelle mentioned in today's lecture that it's fine to keep an answer in meters, so I'm assuming this also applies to tests.
by Aydin Karatas 1A
Wed Oct 14, 2020 11:05 am
Forum: Properties of Light
Topic: work function
Replies: 15
Views: 138

Re: work function

I used a calculator for these problems. If you really wanted to, you could use exponent properties (multiplication adds the exponents of 10 and division subtracts the exponents of 10) to figure out to what power 10 will be raised to in your head. But for the other numbers, I'd use a calculator.
by Aydin Karatas 1A
Wed Oct 14, 2020 10:57 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg
Replies: 2
Views: 28

Re: Heisenberg

Quantitative data encompass measurable attributes. Thus, they can be counted and expressed numerically (distance, mass, pH, # of mol, etc.). Qualitative data encompass descriptions that are observed, not measured. Color, smell, and other observable attributes that are not necessarily measured numeri...
by Aydin Karatas 1A
Mon Oct 12, 2020 12:38 pm
Forum: Properties of Light
Topic: What exactly is Φ?
Replies: 16
Views: 150

Re: What exactly is Φ?

It is the work energy. When looking at work energy in a problem, it's usually measured in Joules (J) of electronvolts (eV). Keep in mind that the work energy plus the excess energy (kinetic energy of an electron) is equal to the incoming energy of the photon.

Hope this helps!
by Aydin Karatas 1A
Mon Oct 12, 2020 10:58 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra
Replies: 3
Views: 39

Re: Atomic Spectra

If you know delta E, you can use the equation E = hv to solve for v by isolating v (E is known and h is a constant). When you have your v-value, use the equation c = (wavelength)v to solve for wavelength by isolating it (v is known and c is a constant).

Hope this helps!
by Aydin Karatas 1A
Mon Oct 12, 2020 10:42 am
Forum: Properties of Light
Topic: Quanta and Photons
Replies: 19
Views: 158

Re: Quanta and Photons

I guess in the context of the H2O problem, "transferable" would mean if you looked at any given point on the water stream, you might see 10 H2O molecules transferring through. At another point in time, you might see only 3 H2O molecules passing through. The main concept to grasp is that cl...
by Aydin Karatas 1A
Sun Oct 11, 2020 5:08 pm
Forum: Limiting Reactant Calculations
Topic: Sapling HW 10
Replies: 9
Views: 119

Re: Sapling HW 10

Yes, you will need to find the molecular formulas. For the reactants, since propyl magnesium bromide is in excess, we only need to deal with 2-butanone. After converting mL 2-butanone to g 2-butanone. (0.40 mL * 0.81 g.mL -1 ), you will need to covert g 2-butanone to mol 2-butanone. With this, we ca...
by Aydin Karatas 1A
Fri Oct 09, 2020 11:51 am
Forum: Properties of Light
Topic: Amplitude of Light Wave
Replies: 5
Views: 69

Re: Amplitude of Light Wave

Yun Su Choi 2I wrote:Just to clarify, the intensity or amplitude is not accounted for in calculating the energy of the photon (E=hv), right?

Yes. E = hv only deals with energy (J), frequency (s^-1), and planks constant (J.s). Amplitude is not taken into account.
by Aydin Karatas 1A
Fri Oct 09, 2020 10:41 am
Forum: Properties of Light
Topic: Speed of Light in Equations
Replies: 6
Views: 26

Re: Speed of Light in Equations

Unless directly stated otherwise, I would always assume it's happening in a vacuum.
by Aydin Karatas 1A
Wed Oct 07, 2020 10:51 am
Forum: Molarity, Solutions, Dilutions
Topic: G.21 Homework Problem
Replies: 7
Views: 72

Re: G.21 Homework Problem

Since you will need moles of K + and S 2- to determine their molarities with the molarity equation (M=n/V), start by converting the masses of KCl, K2S, and K3PO4 to moles with their respective molar masses. The moles of K2S can directly be used to determine the molarity of S 2- because it is the onl...
by Aydin Karatas 1A
Wed Oct 07, 2020 8:48 am
Forum: Empirical & Molecular Formulas
Topic: Sapling HW 9
Replies: 21
Views: 216

Re: Sapling HW 9

Yes, because the resulting moles of each element will provide the relative ratio of atoms in that molecule, which is needed for the empirical formula. Once these numbers are whole numbers (this is done by dividing all mole values by the lowest value. If needed, multiply all these new values by a com...
by Aydin Karatas 1A
Mon Oct 05, 2020 10:34 am
Forum: Significant Figures
Topic: Significant Figures for Calculations with Molar Masses
Replies: 5
Views: 91

Re: Significant Figures for Calculations with Molar Masses

You can consider them as constants because they are known values. Sig figs will be determined from other non-constant, values given in a problem.
by Aydin Karatas 1A
Mon Oct 05, 2020 10:23 am
Forum: Molarity, Solutions, Dilutions
Topic: Molarity Example from Lecture 10/5 [ENDORSED]
Replies: 7
Views: 112

Re: Molarity Example from Lecture 10/5 [ENDORSED]

A mole is just a unit of measurement regarding how much substance is present. By diluting the solution, we are not changing how much KMnO4 is present but we are changing the concentration (molarity). For example, if I had 10 blueberries in a large bowl and then poured water into the bowl, I would st...
by Aydin Karatas 1A
Mon Oct 05, 2020 10:14 am
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student [ENDORSED]
Replies: 221
Views: 116069

Re: Advice from a Medical Student [ENDORSED]

Thank you so much for this advice! I'll definitely make the prophylactic move to take effective notes in his class. Good luck with medical school!
by Aydin Karatas 1A
Fri Oct 02, 2020 10:20 am
Forum: General Science Questions
Topic: Lecture Over Zoom
Replies: 12
Views: 337

Re: Lecture Over Zoom

I heard there will be lectures on Zoom starting next week (probably on Monday). Today will just be the prerecorded content on CCLE under Media Resources.
by Aydin Karatas 1A
Fri Oct 02, 2020 10:02 am
Forum: General Science Questions
Topic: Lecture Over Zoom
Replies: 12
Views: 337

Re: Lecture Over Zoom

The prerecorded lecture is back. I'm not sure if there will even be a live Zoom call today for LEC 1 at least.

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