CHEMISTRY COMMUNITY

Myles Chang 1B

This is not necessarily true. For example, XEF2 has two lone pairs, yet is still nonpolar and linear.

Myles Chang 1B

I think your confusion lies within the fact that in one explanation you are describing the general shape using regions of electron density whereas in the other you are referring to bonded atoms. For example, both bent and trigonal planar have three regions of electron density, however bent is called...

Myles Chang 1B

Bent and angular describe the same shape. The VSEPR number would be AX2E

Myles Chang 1B

I think Pi bonds differ from Sigma bonds in how they affect a molecule's structure. Pi bonds prevent a molecule from rotating, namely.

Myles Chang 1B

I think the shape in general will stay the same just because of the areas of electron density, however the exact structure will not be identical. For example, the difference between a trigonal pyramidal and tetrahedral structure is the replacement of one lone pair of electrons with a bond. The bond ...

Myles Chang 1B

The lone pair is above the central atom, not represented by any of the three circles in the diagram. The question is referring to the fact that the lone pairs above the central atom repelling the other electrons to create a bent shape.

Myles Chang 1B

I think your confusion stems from the fact that the 2 lone electrons are found in one orbital, meaning that the P atom only has 4 regions of electron density.

Myles Chang 1B

I think for this question it is important to note that resonance structures are not individualized possibilities of a structure, but rather are a blend of them. Looking at the Lewis dot diagram for the top image, you could put the two double bonds in various places, meaning that the actual length (a...

Myles Chang 1B

In general, elements closer to the left side of the periodic table (s-block and some of p-block) form cations because it is easier for them to lose, for example, 2 electrons in the case of Mg rather than gain 6. Likewise, it would require a lot of energy to pull 7 valence electrons away from a chlor...

Myles Chang 1B

I think the formal charges apply only to the atom, not the molecule. Otherwise, given that the two molecules have the same amount of electrons, wouldn't every single possible structure for a molecule have the same formal charge? The first structure's atoms all have formal charges of 0 whereas the se...

Myles Chang 1B

Hello!

I was wondering if there was any way to tell how many electrons in the d-block are lost in an ion. For example, is there any way to know whether a copper atom will go to 3+ or 2+; if there is not, will be be given the charge on the test?

Myles Chang 1B

Covalent bonds form molecules and ionic bonds form ionic compounds. Ions are anything that have a net electric charge, which is why saying that ionic compounds are only made of metals and nonmetals is dangerous. For example, NH4+ and CO32- are both ions that can form an ionic bond with each other, b...

Myles Chang 1B

Hello!
I was a bit confused on how resonance structures work. Dr. Lavelle mentioned in class that the real structure of an element is not any of the resonance structures, but rather is an average of them. How does that work? How can one electron be spread across multiple, incomplete orbitals?

Myles Chang 1B

There is no specific order that you need to fill in the dots. The only thing you need to be wary of is that Hund's rule needs to be applied. This means that you shouldn't have two electrons in one orbital (one side of the element), while another has zero.

Myles Chang 1B

Chlorine is very reactive because of how close it is to filling a full electron shell. Since it only needs only more to complete a shell as opposed to losing 7, Cl- is the most common form. This is also why we see Na+ a lot. The Na needs to lose an electron to have a full valence shell. Hence, NaCl.

Myles Chang 1B

Will we need to be able to explain the existence of orbitals using the Heisenberg Uncertainity Principle or anything about the uncertainty principle for that matter?

Myles Chang 1B

Hello! I had a question regarding whether an element's period or column had a larger influence on its atomic radius. For example, which would have a larger atomic radius: zinc or silver?

Myles Chang 1B

I believe that Dr. Lavelle said that we will not need to use the Schrodinger Equation on any tests, rather, his explanation provides some context as to how we know where electrons are.

Myles Chang 1B

Electrons are found in orbitals surrounding the nucleus. The positive charge of the protons in the nucleus attracts the negatively charged electrons.

Myles Chang 1B

I think this is most likely just a calculator error. You should get the same answer regardless of what equation you use.

Myles Chang 1B

Use Planck's constant whenever you see the letter "h" in an equation you need to use on the sheet provided on top of the test.

Myles Chang 1B

It will make a difference on the test. I would guess at least a few of the calculations on the test will involve finding properties of an electron based on its momentum, which you need mass to find.

Myles Chang 1B

I believe my TA said that the class could be curved but it wouldn't be until the end of the quarter.

Myles Chang 1B

I believe that if it has been covered in class, it is fair game to be chosen for hw. If you have a Tuesday discussion, you could also choose homework problems from Monday's lecture. Other than that, you should be able to do questions from Outline 1 as long as they are not repeated.

Myles Chang 1B

I think it's easiest to think of photons as little bundles of energy so therefore you would use joules to measure how much energy a photon has.

Myles Chang 1B

A photon can also be a representation of a particle of light or other electromagnetic radiation.

Myles Chang 1B

I prefer to write out the expression in one long line to make sure my units line up, however, I do my calculations individually because I want to make sure that each of them make sense.

Myles Chang 1B

Hi I'm not sure if this is where I should be asking this question or if this counts for one of our three posts but anyways I have some questions regarding the first exam this coming week. 1.) Will we have access to a periodic table or should we bring our own? 2.) For balancing equation problems, wil...

Myles Chang 1B

For problem G.16 Part C, "Determine the mass of CuSO4 * 5H20 That must be used to prepare 250 mL of 0.20M CuSO4", does the water in the solute not show up as part of the final volume added to the 250 mL? The solution to the problem simply changes the molar mass of the solution when convert...

CHEMISTRY COMMUNITY

Search found 29 matches

Re: Lone Pair=Polar?

Re: Determining Shapes [ENDORSED]

Re: Bent vs. Angular

Re: Differences Between Pi and Sigma bonds

Re: Lone Pairs

Re: HW question 4.1

Re: Textbook 4.37

Re: Test 3 Q 8 [ENDORSED]

Re: oxidation

Re: 3.53 b

Variable Valence

Re: Ionic vs Covalent

How do Resonance Structures Work?

Re: Order of Dots

Re: Stability of Cl vs Cl-

Re: Midterm Topics [ENDORSED]

Across vs Down Trend

Re: double derivative [ENDORSED]

Re: ch.2.1

Re: Test #2: Q6 [ENDORSED]

Re: When to use Planck's Constant [ENDORSED]

Re: electron mass

Re: Test Number 1

Re: Homework? [ENDORSED]

Re: Photon units? [ENDORSED]

Re: still don't uderrsatnd what a photon is [ENDORSED]

Re: writing out conversions in one long line vs. steps

Test #1 [ENDORSED]

G.16 Part C