Search found 30 matches
- Sun Jun 10, 2018 11:04 pm
- Forum: Air Pollution & Acid Rain
- Topic: Acid Rain [ENDORSED]
- Replies: 1
- Views: 622
Acid Rain [ENDORSED]
What exactly do we need to know regarding acid rain for the final? Thank you.
- Sun Jun 10, 2018 10:55 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pOH
- Replies: 5
- Views: 883
pOH
For the final, do we need to know how to calculate pOH, or just pH?
- Sun Jun 10, 2018 10:42 pm
- Forum: Amphoteric Compounds
- Topic: Amphoteric Oxides
- Replies: 4
- Views: 727
Amphoteric Oxides
I was just wondering if we had to memorize the amphoteric oxides, or if there's a method of determining them using the periodic table?
- Sun Jun 03, 2018 11:05 pm
- Forum: Biological Examples
- Topic: Biological Function on Final?
- Replies: 3
- Views: 515
Re: Biological Function on Final?
So we are not supposed to know specifics? For example that cobalt has to do with vitamin B12 or that different transition metals like Mn, Ni, Cu and Zn have to do with different enzymes?
- Sun Jun 03, 2018 10:48 pm
- Forum: Hybridization
- Topic: Hybrid orbitals
- Replies: 6
- Views: 745
Hybrid orbitals
On my notes I have the sentence that says regions of electron density equal the number of hybrid orbitals. I copied it from Dr. Lavelle's powerpoint but I am having a hard time understanding this concept. Could someone further explain it in simple terms?
- Sun Jun 03, 2018 10:38 pm
- Forum: Sigma & Pi Bonds
- Topic: Sigma and Pi bonds
- Replies: 3
- Views: 551
Sigma and Pi bonds
Can someone clarify how we would be tested on sigma and pi bonds, for example types of questions that could involve these bonds?
- Sun May 27, 2018 11:02 pm
- Forum: Resonance Structures
- Topic: Resonance [ENDORSED]
- Replies: 5
- Views: 907
Resonance [ENDORSED]
When a question asks which structure contributes more to resonance, what does that mean?
- Sun May 27, 2018 8:29 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Difference in angles
- Replies: 3
- Views: 411
Difference in angles
Professor Lavelle pointed out two different types of bonds in lecture, bond angles and just angles, could someone clarify that please? my notes confused me with the terms
- Sun May 27, 2018 8:16 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: AXE Notation and Shape
- Replies: 4
- Views: 928
Re: AXE Notation and Shape
Orher than knowing how to write the AXE notation are there any other ways we could be tested on this concept on the final?
- Sun May 20, 2018 11:48 pm
- Forum: Bond Lengths & Energies
- Topic: Van der Waals [ENDORSED]
- Replies: 4
- Views: 595
Van der Waals [ENDORSED]
Does it matter which name we use for Van der Waals? Like London, Dispersion, Induced dipole etc? And are they considered bonds or simply interactions?
- Sun May 20, 2018 11:41 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Dipole moments
- Replies: 3
- Views: 693
Dipole moments
I understand that when dipole moments cancel out, a molecule is not polar but I am having trouble understanding the dipole moments on the first place. Does anyone have a simple explanation that could help understanding dipole moments and their connection to polarity?
- Sun May 20, 2018 11:21 pm
- Forum: Ionic & Covalent Bonds
- Topic: Test 3
- Replies: 2
- Views: 369
Test 3
Can someone clarify until what lecture's material test 3 will cover? Should we focus on lewis structures and formal charge or should we also know bond strengths and lengths and dipole dipole interactions?
- Sun May 13, 2018 9:54 pm
- Forum: Lewis Structures
- Topic: Expanded Octet
- Replies: 2
- Views: 314
Expanded Octet
In the last lecture one of the TAs was explaining the concept of expanded octects in the elements of the 3rd row of the periodic table or below. The example that was given was with SO4. I do not really understand why double bonds were formed between the S and two of the Os to make it more stable but...
- Mon May 07, 2018 12:15 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Homework problem 2.37
- Replies: 1
- Views: 254
Homework problem 2.37
For this homework problem could someone explain what they mean by "shielding"?
- Mon May 07, 2018 12:10 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: 2.29
- Replies: 9
- Views: 1126
Re: 2.29
I still don't understand letters b and d. For the explanation for letter d, what do you mean by "only one orbital can exist in that location in space"? If l=2 aren't there 5 orbitals (ml)? And doesn't n=3 and l=2 refer to row 3 in the d block? Thank you and sorry if the questions are confu...
- Sun May 06, 2018 9:42 pm
- Forum: SI Units, Unit Conversions
- Topic: #9 on Midterm Practice Review (unicorn)
- Replies: 4
- Views: 604
#9 on Midterm Practice Review (unicorn)
On the practice review that one of the UA's prepared, the last question (number 9) is about molarity and volume. Since M is mol/L I assumed that we had to convert the given volume from mL to L, however, that is not the case. All of the calculations are made with mL, why is that so? And how do I know...
- Sun May 06, 2018 9:02 pm
- Forum: Photoelectric Effect
- Topic: Intensity of Photon
- Replies: 8
- Views: 967
Intensity of Photon
When reviewing the photoelectric effect for the midterm I remembered that one of the surprising outcomes of the experiment was that increasing intensity did not make a difference in the removal of electrons. I do understand that what matters is the energy of the photon, I was just wondering what int...
- Tue May 01, 2018 3:51 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Energy levels and Orbitals
- Replies: 3
- Views: 524
Energy levels and Orbitals
This might be a simple question but I am having a really hard time differentiation energy levels and orbitals. When I say energy levels I mean what we studied for test 2, like n=2 or n=1 (Balmer and Lyman series material). How do orbitals (s, p, d and f) connect back to that?
- Mon Apr 30, 2018 9:25 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Nodal Planes
- Replies: 2
- Views: 317
Nodal Planes
Dr. Lavelle explained the concept of nodal planes during lecture but I was reviewing my notes and got quite confused. Can someone further explain this concept and what is its importance when it comes to orbitals and s orbitals not having them?
- Mon Apr 23, 2018 10:53 am
- Forum: Einstein Equation
- Topic: 1.27: Units Confusion
- Replies: 3
- Views: 477
Re: 1.27: Units Confusion
I'm also confused as to why dividing 64J by 4.7x10^-19J/photon instead of the other way around.
Other than that, on the last part that asks us to find moles of photons, why use Avogadro's number as the number of photons in 1 mole?
Other than that, on the last part that asks us to find moles of photons, why use Avogadro's number as the number of photons in 1 mole?
- Mon Apr 23, 2018 10:28 am
- Forum: Einstein Equation
- Topic: Homework number 1.25a [ENDORSED]
- Replies: 3
- Views: 571
Homework number 1.25a [ENDORSED]
Why is the power of the final answer -19? I keep getting a different result every time I repeat the calculation.
- Sun Apr 22, 2018 9:57 pm
- Forum: Properties of Light
- Topic: Wavelength/frequency
- Replies: 11
- Views: 1257
Wavelength/frequency
Why does energy decrease when wavelength increase? My TA explained the concept in discussion but I don't think I fully got it.
- Sun Apr 22, 2018 9:50 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Atom's diameter
- Replies: 2
- Views: 418
Atom's diameter
I am quite confused with the uncertainty in position in problems referring to Heinsberg's Indeterminacy Equation. I understand how to apply the formulas but why its the uncertainty in position equals to the diameter of the atom?
- Mon Apr 16, 2018 10:11 pm
- Forum: Photoelectric Effect
- Topic: Energy levels
- Replies: 7
- Views: 8791
Energy levels
When discussing atomic spectra and energy levels why is the gap between n1 and n2 the biggest?
- Sun Apr 15, 2018 11:31 pm
- Forum: Photoelectric Effect
- Topic: E(photon)>or=E(energy remove e-) [ENDORSED]
- Replies: 2
- Views: 303
E(photon)>or=E(energy remove e-) [ENDORSED]
Can someone further explain the statement presented in lecture that says, "unless E(photon)>or=E(energy remove e-) then e- not emitted even for high intensity light"?
- Sun Apr 15, 2018 11:24 pm
- Forum: Photoelectric Effect
- Topic: Photoelectric Effect Diagram [ENDORSED]
- Replies: 2
- Views: 379
Photoelectric Effect Diagram [ENDORSED]
Dr. Lavelle mentioned that drawing a simple diagram helps when solving problems regarding the photoelectric effect. Drawing the diagram has indeed helped me with the problems, I was just wondering what DET stands for located on the top right corner on the diagram used in class?
- Sun Apr 15, 2018 11:21 pm
- Forum: Properties of Light
- Topic: Speed of light constant
- Replies: 5
- Views: 447
Speed of light constant
When reviewing the properties of light Dr. Lavelle gave as the constant c as 3.00 x 10ˆ8 m/s. I understand that this constant will always be given and that it is part of a formula but I was quite confused as to which type of problem/when would we use this constant?
- Sun Apr 15, 2018 5:36 pm
- Forum: Empirical & Molecular Formulas
- Topic: Determining Formulas Based on Molecule
- Replies: 4
- Views: 631
Determining Formulas Based on Molecule
When given a visual representation of a molecule it is possible to write both its empirical and molecular formulas, however, I am having a bit of confusion when it comes to doing so. Is it correct to count the number of elements for the molecular formula? What about the empirical formula?
- Fri Apr 13, 2018 9:16 am
- Forum: Photoelectric Effect
- Topic: Equations in Quantum Mechanics [ENDORSED]
- Replies: 3
- Views: 288
Equations in Quantum Mechanics [ENDORSED]
When it comes to equations in quantum mechanics, Dr. Lavelle mentioned that a key concept is that their variables are quantisized or discrete. Could someone further elaborate what he means by a quantisized or discrete variable?
- Tue Apr 10, 2018 9:18 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Fundamentals G21
- Replies: 1
- Views: 276
Fundamentals G21
When going over problem G21 I was quite confused why after finding the number of moles for K2S we have to multiply by 2molK+/1molK2S? I figured it might be because there are two K but I don't really understand why multiply. Can someone explain?