Search found 31 matches

by Gabi Landes 1-H
Sun Jun 03, 2018 11:25 pm
Forum: Bond Lengths & Energies
Topic: Test 3 Q 8 [ENDORSED]
Replies: 9
Views: 439

Re: Test 3 Q 8 [ENDORSED]

So a localized double bond is essentially stronger then a delocalized bond?
by Gabi Landes 1-H
Sun Jun 03, 2018 11:22 pm
Forum: Dipole Moments
Topic: dipole moments
Replies: 9
Views: 374

Re: dipole moments

Because of the higher strength of electronegativity - would the C-Cl bond be considered more polar?
by Gabi Landes 1-H
Sun Jun 03, 2018 11:09 pm
Forum: Hybridization
Topic: Atomic orbitals vs hybrid orbitals
Replies: 2
Views: 125

Re: Atomic orbitals vs hybrid orbitals

I found these notes from another UCLA chemistry professor and they seem to break everything down step by step. The diagrams have helped me visualize what is actually going on. If you are a visual learner this may help you remember the process better. Hope it helps! http://www.chem.ucla.edu/~harding/...
by Gabi Landes 1-H
Sun Jun 03, 2018 11:02 pm
Forum: Hybridization
Topic: Hybrid orbitals
Replies: 6
Views: 239

Re: Hybrid orbitals

# of regions of electron density = # bonds and lone pairs around an atom

- a double bond, triple bond, or a lone pair counts as only one region of electron density
by Gabi Landes 1-H
Sun Jun 03, 2018 10:53 pm
Forum: Sigma & Pi Bonds
Topic: delocalized and localized pi bond
Replies: 3
Views: 718

Re: delocalized and localized pi bond

These two examples may help you visualize -
Delocalized:
benzene01.png

Localized:
ethylene01.png
ethylene01.png (6.54 KiB) Viewed 712 times
by Gabi Landes 1-H
Sun May 27, 2018 11:49 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Water effect 11.115
Replies: 2
Views: 286

Re: Water effect 11.115

Cant water also be a gas? Water vapor?
by Gabi Landes 1-H
Sun May 27, 2018 11:48 pm
Forum: Ideal Gases
Topic: PV=nRT
Replies: 3
Views: 274

Re: PV=nRT

If you were trying to find the volume you would simply multiply P to both sides and end up with Charles's law (aka law of volumes).
by Gabi Landes 1-H
Sun May 27, 2018 11:32 pm
Forum: Sigma & Pi Bonds
Topic: Bond Strength/Bond Type
Replies: 3
Views: 264

Bond Strength/Bond Type

I understand the difference between sigma and pi bonds, however in terms of bond strength I get confused. Sigma bonds are in general more difficult to break because the nuclei have a strong hold on the e - ... Yet we are taught single bonds are weaker than double bonds? Is that just because a single...
by Gabi Landes 1-H
Mon May 21, 2018 12:20 am
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Dipole moments
Replies: 3
Views: 274

Re: Dipole moments

The unequal sharing of electrons within a bond leads to the formation of an electric dipole (a separation of positive and negative electric charges). Bonds can fall between one of two extremes, from completely nonpolar to completely polar . see: https://courses.lumenlearning.com/boundless-chemistry...
by Gabi Landes 1-H
Mon May 21, 2018 12:06 am
Forum: Lewis Structures
Topic: How do I start a Lewis structure?
Replies: 3
Views: 148

Re: How do I start a Lewis structure?

I would watch this Khan video, it goes through the steps for beginning the Lewis Structure! https://www.khanacademy.org/science/chemistry/chemical-bonds/copy-of-dot-structures/v/drawing-dot-structures --> In general the least electronegative element goes in the middle! --> Cyclic compounds = ring co...
by Gabi Landes 1-H
Mon May 21, 2018 12:01 am
Forum: Octet Exceptions
Topic: Octet Exception
Replies: 7
Views: 354

Re: Octet Exception

odd-electron molecules molecules with an odd number of electrons (e.g., NO). Electron-deficient molecules molecules in which atoms have fewer than 8 electrons (e.g., boron chloride and lighter s- and p- block elements ) ie. Hydrogen, Beryllium, and Boron = too few electrons to form octet ----> Hydr...
by Gabi Landes 1-H
Sun May 20, 2018 11:43 pm
Forum: Lewis Structures
Topic: Lewis Dot vs Lewis Structure
Replies: 3
Views: 122

Re: Lewis Dot vs Lewis Structure

Lewis symbol: Formalism in which the valence electrons of an atom are represented as dots. Lewis structure: Formalism used to show the structure of a molecule or compound, in which shared electrons pairs between atoms are indicated by dashes. Non-bonding, lone pairs of electrons must also be shown....
by Gabi Landes 1-H
Sun May 13, 2018 7:06 pm
Forum: Octet Exceptions
Topic: Concept of Exceptions
Replies: 4
Views: 191

Re: Concept of Exceptions

Third period elements occasionally exceed the octet rule by using their empty d orbitals to accommodate additional electrons Size is also an important consideration: The larger the central atom, the larger the number of electrons which can surround it Expanded valence shells occur most often when t...
by Gabi Landes 1-H
Sun May 13, 2018 7:01 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic vs Covalent vs Metallic Bonds
Replies: 6
Views: 234

Re: Ionic vs Covalent vs Metallic Bonds

"Ionic bonds form due to the transfer of an electron from one atom to another. Covalent bonds involve the sharing of electrons between two atoms. Metallic bonds are formed by the attraction between metal ions and delocalized, or "free" electrons." See: https://www.khanacademy.org...
by Gabi Landes 1-H
Sun May 13, 2018 6:54 pm
Forum: Trends in The Periodic Table
Topic: Exceptions to Ionization Energy Trend
Replies: 2
Views: 206

Re: Exceptions to Ionization Energy Trend

Electron configurations seem to create these exceptions.. For the N and O on the second row of the periodic table: "The electron configuration of nitrogen is 1s22s22p3, a stable, half-filled structure. Oxygen has an electron configuration of 1s22s22p4 --one electron beyond stable. So, taking an...
by Gabi Landes 1-H
Sun May 06, 2018 11:56 pm
Forum: Quantum Numbers and The H-Atom
Topic: "ms" Quantum Number [ENDORSED]
Replies: 2
Views: 190

Re: "ms" Quantum Number [ENDORSED]

I believe if the question gives you all quantum four numbers (the Principal Quantum Number "n", Orbital Angular Momentum Quantum Number "l", Magnetic Quantum Number "m l " and Electron Spin Quantum Number "m s ") then only 1 electron can be in that exact state...
by Gabi Landes 1-H
Sun May 06, 2018 11:41 pm
Forum: Ionic & Covalent Bonds
Topic: Midterm Topics [ENDORSED]
Replies: 33
Views: 1911

Re: Midterm Topics [ENDORSED]

Phil Timoteo wrote:I believe the midterm will cover material from chapter 1&2

I also believe the fundamentals section, that was covered on the first test, will also be on the midterm exam!
by Gabi Landes 1-H
Wed May 02, 2018 1:34 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Example 1.7
Replies: 2
Views: 160

Example 1.7

Hello! In text example 1.7 (p. 18) - Estimate the minimum uncertainty in: (a) the position of an object as heavy as a marble of mass 1.0 g given that its speed is known within + 1.0mm/s and (b) the speed of an electron confined to within the diameter of a typical atom (200. pm). Why is \Delta v = 2 ...
by Gabi Landes 1-H
Tue May 01, 2018 9:00 pm
Forum: Properties of Light
Topic: Test #2: Q6 [ENDORSED]
Replies: 10
Views: 540

Re: Test #2: Q6 [ENDORSED]

I also used wavelength=hc/E, but the way you do it works too. With rounding the answer is 10 x 10^7 (positive exponent of 7, not negative, because there's 10^9 nanometers in one meter) If you don't mind explaining more, just so I can possibly understand, why would 10^9 nanometers in one meter make ...
by Gabi Landes 1-H
Tue May 01, 2018 8:56 pm
Forum: DeBroglie Equation
Topic: Test #2: Q5 [ENDORSED]
Replies: 9
Views: 500

Re: Test #2: Q5 [ENDORSED]

yazminedesan1F wrote:How were you able to see the quiz earlier than discussion?


My TA passed our quizzes out after class on Friday!
by Gabi Landes 1-H
Sun Apr 29, 2018 11:48 am
Forum: Properties of Light
Topic: Test #2: Q6 [ENDORSED]
Replies: 10
Views: 540

Test #2: Q6 [ENDORSED]

I got the second part of this question incorrect, I am assuming because of an accident when inputting the numbers into my calculator. I have re-done the problem below and just want to make sure I am on the right track. Q6. Microwave ovens use microwave electromagnetic radiation to cause vibrations w...
by Gabi Landes 1-H
Sun Apr 29, 2018 11:23 am
Forum: DeBroglie Equation
Topic: Test #2: Q5 [ENDORSED]
Replies: 9
Views: 500

Test #2: Q5 [ENDORSED]

I got this question wrong on the test -- I just want to make sure I am on the right track now. Thanks! Q5. Electrical signals within the body are transmitted by the movement of sodium ions in and out of neurons. When pain signals are sent, the local velocity of a sodium ion is assumed to be 1.34 m/s...
by Gabi Landes 1-H
Sun Apr 29, 2018 10:41 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Test 2 Q4 help [ENDORSED]
Replies: 3
Views: 209

Re: Test 2 Q4 help [ENDORSED]

The way this question was written really through me for a loop. I definitely was looking for a reason to use the Rydberg equation, however the given wavelength was my biggest indication that this was a c=lamda*v & E=hv problem. Using the word "difference" in the question made me think ...
by Gabi Landes 1-H
Sun Apr 22, 2018 4:43 pm
Forum: *Black Body Radiation
Topic: Black Body? [ENDORSED]
Replies: 13
Views: 1204

Re: Black Body? [ENDORSED]

Liliana Rosales 1E wrote:I believe black bodies absorb the entire electromagnetic spectrum not just the visible spectrum.


They do! A black body is an object that absorbs all radiation falling on it, at all wavelengths.
by Gabi Landes 1-H
Sun Apr 22, 2018 4:39 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Frequency if energy goes from n=2 to n=4
Replies: 6
Views: 215

Re: Frequency if energy goes from n=2 to n=4

When moving up energy levels light is absorbed & not emitted -- however ^^^ they are right, it cannot be negative!
by Gabi Landes 1-H
Sun Apr 22, 2018 4:34 pm
Forum: Einstein Equation
Topic: General Question about Joules [ENDORSED]
Replies: 7
Views: 615

Re: General Question about Joules [ENDORSED]

Why do we often use "joule seconds"? In stead of J.s^-1?
by Gabi Landes 1-H
Fri Apr 20, 2018 1:47 am
Forum: Properties of Light
Topic: Memorizing Wavelengths [ENDORSED]
Replies: 4
Views: 177

Memorizing Wavelengths [ENDORSED]

Would it be optimal to memorize the wavelength regions radio--->gamma? Or would that be a waste of time?
by Gabi Landes 1-H
Fri Apr 20, 2018 1:34 am
Forum: Ideal Gases
Topic: Reading the textbook [ENDORSED]
Replies: 127
Views: 74894

Re: Reading the textbook [ENDORSED]

Personally I would only work out the pre & post module questions along with the assigned homework problems. Dr. Lavelle seems to do a good job of making what he wants you to know clear. If you try to do all the problems in the chapter you'll probably get overwhelmed. is it helpful to work out th...
by Gabi Landes 1-H
Fri Apr 20, 2018 1:22 am
Forum: Naming
Topic: Naming and Polyatomic Ions
Replies: 6
Views: 434

Re: Naming and Polyatomic Ions

Is it expected of us to memorize the polyatomic ions?
by Gabi Landes 1-H
Fri Apr 20, 2018 1:14 am
Forum: Significant Figures
Topic: Basic Sig Figs
Replies: 13
Views: 988

Re: Basic Sig Figs

When you get the final answer for a problem, for example,

#2. CHEM, an FM radio station, broadcasts at 99.5 MHz. What is the wavelength of the corresponding radio waves?" (from TA worksheet 2)

would the resulting answer have be rounded to 3 sig figs because of the "99.5 MHz"?
by Gabi Landes 1-H
Fri Apr 20, 2018 1:08 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg Equation & Test 2
Replies: 4
Views: 201

Heisenberg Equation & Test 2

Will the application of the Heisenberg Equation be tested on next weeks test (test two)?

Go to advanced search