CHEMISTRY COMMUNITY

Gabi Landes 1-H

So a localized double bond is essentially stronger then a delocalized bond?

Gabi Landes 1-H

Because of the higher strength of electronegativity - would the C-Cl bond be considered more polar?

Gabi Landes 1-H

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/...

Gabi Landes 1-H

# 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

Gabi Landes 1-H

These two examples may help you visualize -
Delocalized:

Localized:

: ethylene01.png (6.54 KiB) Viewed 11595 times

Gabi Landes 1-H

Cant water also be a gas? Water vapor?

Gabi Landes 1-H

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).

Gabi Landes 1-H

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...

Gabi Landes 1-H

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...

Gabi Landes 1-H

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...

Gabi Landes 1-H

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...

Gabi Landes 1-H

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....

Gabi Landes 1-H

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...

Gabi Landes 1-H

"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...

Gabi Landes 1-H

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...

Gabi Landes 1-H

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...

Gabi Landes 1-H

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!

Gabi Landes 1-H

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 ...

Gabi Landes 1-H

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 ...

Gabi Landes 1-H

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

My TA passed our quizzes out after class on Friday!

Gabi Landes 1-H

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...

Gabi Landes 1-H

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...

Gabi Landes 1-H

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 ...

Gabi Landes 1-H

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.

Gabi Landes 1-H

When moving up energy levels light is absorbed & not emitted -- however ^^^ they are right, it cannot be negative!

Gabi Landes 1-H

Why do we often use "joule seconds"? In stead of J.s^-1?

Gabi Landes 1-H

Would it be optimal to memorize the wavelength regions radio--->gamma? Or would that be a waste of time?

Gabi Landes 1-H

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...

Gabi Landes 1-H

Is it expected of us to memorize the polyatomic ions?

Gabi Landes 1-H

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"?

Gabi Landes 1-H

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

CHEMISTRY COMMUNITY

Search found 31 matches

Re: Test 3 Q 8 [ENDORSED]

Re: dipole moments

Re: Atomic orbitals vs hybrid orbitals

Re: Hybrid orbitals

Re: delocalized and localized pi bond

Re: Water effect 11.115

Re: PV=nRT

Bond Strength/Bond Type

Re: Dipole moments

Re: How do I start a Lewis structure?

Re: Octet Exception

Re: Lewis Dot vs Lewis Structure

Re: Concept of Exceptions

Re: Ionic vs Covalent vs Metallic Bonds

Re: Exceptions to Ionization Energy Trend

Re: "ms" Quantum Number [ENDORSED]

Re: Midterm Topics [ENDORSED]

Example 1.7

Re: Test #2: Q6 [ENDORSED]

Re: Test #2: Q5 [ENDORSED]

Test #2: Q6 [ENDORSED]

Test #2: Q5 [ENDORSED]

Re: Test 2 Q4 help [ENDORSED]

Re: Black Body? [ENDORSED]

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

Re: General Question about Joules [ENDORSED]

Memorizing Wavelengths [ENDORSED]

Re: Reading the textbook

Re: Naming and Polyatomic Ions

Re: Basic Sig Figs

Heisenberg Equation & Test 2