CHEMISTRY COMMUNITY

Jennifer Ma 1G

I think hybridization changes if the lone pairs are attached to the central atom, but that's it.

Jennifer Ma 1G

I don't think that you have to follow the textbook's version of the hybridization notation, and just use the notation that Dr. Lavelle uses. He has taught other concepts and equation that were not per the textbook, and has advised us to use his method that he teaches in class.

Jennifer Ma 1G

I believe that it's trying to let you know that the same hybridization concepts apply with the molecules you mentioned; no special rules.

Jennifer Ma 1G

Both the number of bonds and number of lone pairs take part in determining the shape of the molecule.

Jennifer Ma 1G

Molecules can have lone pairs, and can also end up affecting the shape as well.

Jennifer Ma 1G

I don't think a single electron is enough to change the shape of a molecule, which is why only lone pairs are taken into account of molecular shape.

Jennifer Ma 1G

You should know how to draw Lewis structures of molecules, including the special cases like expanded octets and resonance, as well as ionic vs. covalent bonds, and bond length & strength.

Jennifer Ma 1G

By adding another bond, you are able to make the formal charge of the molecule closer to 0, making it more stable. To help you figure out whether two atoms need another bond, just calculate the formal charge on each atom, and keep adding bonds wherever it is necessary in order to make the formal cha...

Jennifer Ma 1G

I also looked up some information on the correlation of amount of bounds and the bond angles, so I also know that bond angles are affected by the number of bonds. However, I don't think that this is something we need to focus on too much because the syllabus does not necessarily mention this concept.

Jennifer Ma 1G

Yes, that is allowed! Another resonance structure with the same formal charge can be a triple bond with a lone pair for each element.

Jennifer Ma 1G

Although all resonance structures are acceptable forms of a Lewis structure, you would need to draw out all the possible resonance structure (if asked to), and indicate that they are of resonance by a double ended arrow: <->

Jennifer Ma 1G

I don't think that you have to fill the valence electrons in a specific order, all you need to do is make sure you're filling them in symmetrically. For example, if you had a molecule that had the following structure ( E - H - E ), and you had 8 valence electrons to fill, you would do have to fill ...

Jennifer Ma 1G

Because they all have the same number of valence electrons at this point, you would take into consideration how many protons each element has. We know that the more protons there are, the smaller the radius will be because the electrons are more attracted to the nucleus. Because Cl has the most numb...

Jennifer Ma 1G

In one of the review sessions I attended, some of his previous midterm questions asked which of the 2 elements had a higher/lower electron affinity, atomic radii, etc. Therefore, you don't need to know specific values, just general trends.

Jennifer Ma 1G

I don't think that you have to fill the valence electrons in a specific order, all you need to do is make sure you're filling them in symmetrically. For example, if you had a molecule that had the following structure ( E - H - E ), and you had 8 valence electrons to fill, you would do have to fill 4...

Jennifer Ma 1G

Another trend that follows a similar line of logic is electronegativity. Electronegativty increases from bottom to top, and from left to right in relation to the periodic table.

Jennifer Ma 1G

However, there are 2 exceptions that were mentioned in lecture where you can write the shorthand for the electron configurations, but they do not follow the typical rule when it comes to writing their electron configurations. CHROMIUM (Cr): [Ar] 3d5 4s1, not [Ar] 3d4 4s2 COPPER (Cu): [Ar] 3d10 4s1, ...

Jennifer Ma 1G

How exactly do the orbitals correlate to the blocks on the periodic table? I know that there is an s-, p-, d-, and f- block on the periodic table, as well as the s-, p-, d-, f- orbitals, but I just can't seem to see how both are related to eachother.

Jennifer Ma 1G

Should we understand the ranges of wavelengths of light? like the specific ranges of wavelength (visible light, UV,etc...) because I know some module questions asked that and I don't know the range off the top of my head. thanks! Our TA told us to be familiar with the increasing or decreasing order...

Jennifer Ma 1G

The actual Rydberg's formula is the one that you typed in the latter half of your question. The steps that Dr. Lavelle took was just the step by step version of the formula, then used to find wavelength.

Jennifer Ma 1G

I was also confused when he said that orbitals couldn't be seen as hotel rooms, because each orbital contains electrons which stay in their respective orbital. Is there a different situation that Dr. Lavelle was talking about when he told us not to look at the orbitals as "hotel rooms"?

Jennifer Ma 1G

A photon is basically a wavelength of light, and is typically portrayed as a squiggly line coming from the sun in many diagrams that involve a photon.

Jennifer Ma 1G

I believe the units for a photon is in terms of joules (J).

Jennifer Ma 1G

Taizha 1C wrote:Do we need to memorize the speed of light in different conditions for the exam?

I believe that such constants will be given to us on the exam.

Jennifer Ma 1G

In lecture on Monday, Dr. Lavelle briefly introduced the equation that frequency x wavelength = speed of light. What is the value of speed of light? I googled it, and it spit back 299,792,458 m/s. Do we use this insanely large value, or do we use scientific notation of this value? Is the latter, wha...

Jennifer Ma 1G

In a single H20 molecule, there are 2 atoms of hydrogen. However, the coefficient 4 in front of the H20 means there are 4 H20 molecules. So, there are 8 total atoms of hydrogen in the 4H20 molecules (2 atoms of hydrogen per 1 H20 molecule x 4 H20 molecules = 8 atoms of hydrogen atoms).

Jennifer Ma 1G

The actual yield is a part of many human errors and natural occurrences, so there is no accurate way to measure the actual yield. Most of the time, we should only be asked to calculate for the theoretical yield.

Jennifer Ma 1G

Although we don't need have to memorize the periodic table, I find it useful to memorize the atomic masses of some common elements, such as hydrogen and oxygen, to save time in some calculations.

Jennifer Ma 1G

My TA suggested that it is expected of us to know the some basic ions, polyatomic ions specifically, which can be referenced under the Fundamental section in the textbook.

Jennifer Ma 1G

Another is mmol, which signifies millimoles.

Jennifer Ma 1G

I understand how the concept of significant figures work, but I just can't grasp why it is reiterated that we use them in chemistry related numbers. What is the purpose of significant figures?

CHEMISTRY COMMUNITY

Search found 31 matches

Re: Lone Pairs

Re: Hybridization Notation

Re: Clarification

Re: HW question 4.1

Re: 4.1

Re: single electron and shape

Re: Test 3 Material Question

Re: Stable lewis structures

Re: Bond Angles

Re: CN- Resonance structures [ENDORSED]

Re: How do Resonance Structures Work?

Re: Order of Dots

Re: Homework Problem 2.59 [ENDORSED]

Re: Memorization of Electronegativity

Re: Order of Dots

Re: atomic mass

Re: Electron Configuration form

Orbitals in Relation to Periodic Table

Re: Test 2 Material

Re: Rydberg Equation

Re: Orbitals as states

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

Re: Photon units? [ENDORSED]

Re: Speed of light constant

Value of Speed of Light** (Shoutout to Dr. Lavelle for calling me out in lecture today) [ENDORSED]

Re: What do the coefficients/subscripts represent [ENDORSED]

Re: Actual Yield [ENDORSED]

Re: Periodic Table Memorization [ENDORSED]

Re: Memorizing the charges of ions

Re: Variables

Why are sig figs important?