Search found 31 matches

by Jennifer Ma 1G
Sun Jun 03, 2018 10:56 pm
Forum: Hybridization
Topic: Lone Pairs
Replies: 5
Views: 170

Re: Lone Pairs

I think hybridization changes if the lone pairs are attached to the central atom, but that's it.
by Jennifer Ma 1G
Sun Jun 03, 2018 10:53 pm
Forum: Hybridization
Topic: Hybridization Notation
Replies: 3
Views: 116

Re: Hybridization Notation

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.
by Jennifer Ma 1G
Sun Jun 03, 2018 10:48 pm
Forum: Hybridization
Topic: Clarification
Replies: 4
Views: 221

Re: Clarification

I believe that it's trying to let you know that the same hybridization concepts apply with the molecules you mentioned; no special rules.
by Jennifer Ma 1G
Tue May 29, 2018 4:26 pm
Forum: Bond Lengths & Energies
Topic: HW question 4.1
Replies: 5
Views: 239

Re: HW question 4.1

Both the number of bonds and number of lone pairs take part in determining the shape of the molecule.
by Jennifer Ma 1G
Tue May 29, 2018 4:12 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.1
Replies: 5
Views: 183

Re: 4.1

Molecules can have lone pairs, and can also end up affecting the shape as well.
by Jennifer Ma 1G
Tue May 29, 2018 4:04 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: single electron and shape
Replies: 3
Views: 83

Re: single electron and shape

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.
by Jennifer Ma 1G
Tue May 22, 2018 12:33 pm
Forum: Bond Lengths & Energies
Topic: Test 3 Material Question
Replies: 3
Views: 240

Re: Test 3 Material Question

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.
by Jennifer Ma 1G
Tue May 22, 2018 12:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Stable lewis structures
Replies: 2
Views: 129

Re: Stable lewis structures

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...
by Jennifer Ma 1G
Tue May 22, 2018 12:15 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 4
Views: 171

Re: Bond Angles

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.
by Jennifer Ma 1G
Tue May 15, 2018 5:39 pm
Forum: Resonance Structures
Topic: CN- Resonance structures [ENDORSED]
Replies: 2
Views: 390

Re: CN- Resonance structures [ENDORSED]

Yes, that is allowed! Another resonance structure with the same formal charge can be a triple bond with a lone pair for each element.
by Jennifer Ma 1G
Tue May 15, 2018 5:32 pm
Forum: Resonance Structures
Topic: How do Resonance Structures Work?
Replies: 4
Views: 200

Re: How do Resonance Structures Work?

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: <->
by Jennifer Ma 1G
Tue May 15, 2018 5:30 pm
Forum: Lewis Structures
Topic: Order of Dots
Replies: 11
Views: 406

Re: Order of Dots

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 ...
by Jennifer Ma 1G
Tue May 08, 2018 10:24 am
Forum: Trends in The Periodic Table
Topic: Homework Problem 2.59 [ENDORSED]
Replies: 1
Views: 102

Re: Homework Problem 2.59 [ENDORSED]

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...
by Jennifer Ma 1G
Tue May 08, 2018 10:15 am
Forum: Ionic & Covalent Bonds
Topic: Memorization of Electronegativity
Replies: 6
Views: 311

Re: Memorization of Electronegativity

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.
by Jennifer Ma 1G
Tue May 08, 2018 10:11 am
Forum: Lewis Structures
Topic: Order of Dots
Replies: 11
Views: 406

Re: Order of Dots

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...
by Jennifer Ma 1G
Mon Apr 30, 2018 10:37 pm
Forum: Trends in The Periodic Table
Topic: atomic mass
Replies: 3
Views: 101

Re: atomic mass

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.
by Jennifer Ma 1G
Mon Apr 30, 2018 10:33 pm
Forum: Quantum Numbers and The H-Atom
Topic: Electron Configuration form
Replies: 4
Views: 120

Re: Electron Configuration form

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, ...
by Jennifer Ma 1G
Mon Apr 30, 2018 10:26 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals in Relation to Periodic Table
Replies: 2
Views: 85

Orbitals in Relation to Periodic Table

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.
by Jennifer Ma 1G
Tue Apr 24, 2018 4:06 pm
Forum: Properties of Light
Topic: Test 2 Material
Replies: 12
Views: 416

Re: Test 2 Material

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...
by Jennifer Ma 1G
Tue Apr 24, 2018 4:00 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation
Replies: 4
Views: 197

Re: Rydberg Equation

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.
by Jennifer Ma 1G
Tue Apr 24, 2018 3:53 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals as states
Replies: 2
Views: 77

Re: Orbitals as states

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"?
by Jennifer Ma 1G
Mon Apr 16, 2018 9:19 am
Forum: Properties of Light
Topic: still don't uderrsatnd what a photon is [ENDORSED]
Replies: 20
Views: 411

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

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.
by Jennifer Ma 1G
Mon Apr 16, 2018 9:15 am
Forum: Properties of Light
Topic: Photon units? [ENDORSED]
Replies: 4
Views: 129

Re: Photon units? [ENDORSED]

I believe the units for a photon is in terms of joules (J).
by Jennifer Ma 1G
Mon Apr 16, 2018 9:13 am
Forum: Properties of Light
Topic: Speed of light constant
Replies: 5
Views: 183

Re: Speed of light constant

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.
by Jennifer Ma 1G
Wed Apr 11, 2018 9:47 am
Forum: Properties of Light
Topic: Value of Speed of Light** (Shoutout to Dr. Lavelle for calling me out in lecture today) [ENDORSED]
Replies: 4
Views: 184

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

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...
by Jennifer Ma 1G
Sun Apr 08, 2018 9:56 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: What do the coefficients/subscripts represent [ENDORSED]
Replies: 7
Views: 361

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

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).
by Jennifer Ma 1G
Sun Apr 08, 2018 9:50 pm
Forum: Limiting Reactant Calculations
Topic: Actual Yield [ENDORSED]
Replies: 3
Views: 125

Re: Actual Yield [ENDORSED]

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.
by Jennifer Ma 1G
Sun Apr 08, 2018 9:47 pm
Forum: Empirical & Molecular Formulas
Topic: Periodic Table Memorization [ENDORSED]
Replies: 8
Views: 398

Re: Periodic Table Memorization [ENDORSED]

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.
by Jennifer Ma 1G
Sun Apr 08, 2018 9:43 pm
Forum: Balancing Chemical Reactions
Topic: Memorizing the charges of ions
Replies: 3
Views: 167

Re: Memorizing the charges of ions

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.
by Jennifer Ma 1G
Sun Apr 08, 2018 9:40 pm
Forum: Molarity, Solutions, Dilutions
Topic: Variables
Replies: 5
Views: 190

Re: Variables

Another is mmol, which signifies millimoles.
by Jennifer Ma 1G
Sun Apr 08, 2018 9:37 pm
Forum: Significant Figures
Topic: Why are sig figs important?
Replies: 13
Views: 1352

Why are sig figs important?

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?

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