Search found 43 matches

by Brianna Chen 1I
Wed Nov 25, 2020 8:50 pm
Forum: Hybridization
Topic: Long Pairs/Double & Triple Bonds
Replies: 9
Views: 28

Re: Long Pairs/Double & Triple Bonds

Since hybridization only takes into account the regions of electron densities around a particular atom, double bonds and triple bonds still count as one region of electron density. In addition, lone pairs count as one region of electron density.
by Brianna Chen 1I
Wed Nov 25, 2020 2:08 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: axial vs. equatorial
Replies: 5
Views: 37

Re: axial vs. equatorial

When lone pairs occupy equatorial positions, it only repels two axial bonds at 90º, whereas if the lone pair occupied the axial position it would interact with 3 equational bond's. Therefore, lowest energy is achieved when lone pairs are in equatorial position because there is less repulsion. I sec...
by Brianna Chen 1I
Wed Nov 25, 2020 2:03 pm
Forum: Hybridization
Topic: Hybridization Clarification
Replies: 9
Views: 48

Re: Hybridization Clarification

I like to refer back to the name "hybridization" when I think about what it means! The word "hybrid" is in its name which tells me that we are combining something. In this case, we are combining atomic orbitals to become hybrid orbitals that can hold the correct number of electro...
by Brianna Chen 1I
Wed Nov 25, 2020 1:59 pm
Forum: Student Social/Study Group
Topic: How have your study habits changed?
Replies: 39
Views: 113

Re: How have your study habits changed?

I have definitely seen my studying habits shift dramatically since starting college. I like to progressively study by starting about a week or two weeks before the exam. Then, each day, I review content chronologically, and about a week before the exam, I like to test myself by redoing UA worksheets...
by Brianna Chen 1I
Wed Nov 25, 2020 1:55 pm
Forum: Student Social/Study Group
Topic: Big Sad: Midterm 2
Replies: 74
Views: 463

Re: Big Sad: Midterm 2

Eunice_Castro_1G wrote:
BoparaiAdeshsurjit2I wrote:Does anybody know the grading scheme. If 50% is needed to pass how much do you need to get an A?

Hello! So there are a total of 500 points and to get an A you can only miss 5 points. Hope this helps!


I believe you can only miss 35 points in total to receive an A (93%) in the class!
by Brianna Chen 1I
Sun Nov 22, 2020 1:21 pm
Forum: Electronegativity
Topic: Polarizability vs. Polarizing Power
Replies: 6
Views: 39

Re: Polarizability vs. Polarizing Power

Polarizability increases as atoms are able to be distorted more. Therefore, it practically measures how distorted an atom can be (typically applies to anions). If an atom is highly polarizable, it can be easily distorted. I believe polarizability follows the same trend for atomic radius because the ...
by Brianna Chen 1I
Sun Nov 22, 2020 1:15 pm
Forum: Formal Charge and Oxidation Numbers
Topic: The most plausible structure
Replies: 4
Views: 26

Re: The most plausible structure

The criteria I usually try to meet when looking for the most plausible structure include: Which structure has the most atoms with formal charges closest to 0? Are the negative formal charges on the most electronegative atoms? If the structure satisfies these two requirements, I like to consider it t...
by Brianna Chen 1I
Sun Nov 22, 2020 1:13 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Best Formal Charge Equations
Replies: 23
Views: 69

Re: Best Formal Charge Equations

The simplest way I have come up with calculating formal charge is with the following equation: Formal charge = # of valence electrons - (# of "things" around the atom) These things correlate to lines/dots. Therefore, I simply count up how many lines and dots there are around the atom and s...
by Brianna Chen 1I
Sun Nov 22, 2020 1:11 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Tips for memorizing different molecular shapes
Replies: 9
Views: 41

Re: Tips for memorizing different molecular shapes

Lavelle stated in his lecture that molecules with the same AXE notation will typically have the same shape. Therefore, that could help with the memorization process of the shapes. Other than that, it would also be helpful to actually picture what the molecule would look like in 3D. However, this may...
by Brianna Chen 1I
Sun Nov 22, 2020 1:08 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Remembering Molecular Shapes
Replies: 4
Views: 28

Re: Remembering Molecular Shapes

I recall that Lavelle stated in his lecture that molecules with the same AXE notation will typically have the same shape. Therefore, that could help with the memorization process of the shapes. Other than that, it would also be helpful to actually picture what the molecule would look like in 3D.
by Brianna Chen 1I
Sun Nov 15, 2020 7:42 pm
Forum: Octet Exceptions
Topic: Radicals
Replies: 7
Views: 55

Re: Radicals

I think those are the two fundamentals that are necessary to know when it comes to radicals: the molecules have an uneven amount of valence electrons (odd number) and radicals are highly reactive.
by Brianna Chen 1I
Sun Nov 15, 2020 7:37 pm
Forum: Resonance Structures
Topic: Resonance Structures Clarification
Replies: 8
Views: 27

Re: Resonance Structures Clarification

I believe you would have to look at formal charge to determine the most favorable structure first (least energy) and then from there, you can determine the resonance structures.
by Brianna Chen 1I
Sun Nov 15, 2020 7:35 pm
Forum: Resonance Structures
Topic: Sapling Resonance Structures
Replies: 4
Views: 34

Sapling Resonance Structures

When I was doing Sapling, I noticed that they included the "non-favorable" structure in the answer when they were explaining the resonance hybrid. I thought we first look for the most favorable structure and then if there is resonance, that is part of the resonance hybrid?
by Brianna Chen 1I
Sun Nov 15, 2020 7:33 pm
Forum: Lewis Structures
Topic: VSEPR
Replies: 4
Views: 21

Re: VSEPR

I don't think we will be tested on VESPR but predicting the geometry of the molecules will definitely help when drawing the Lewis structures.
by Brianna Chen 1I
Sun Nov 15, 2020 7:24 pm
Forum: Lewis Structures
Topic: Confusions with Expanded Octets in Period 3
Replies: 2
Views: 15

Confusions with Expanded Octets in Period 3

I am a bit confused about the idea of expanded octets. In the book, it states that only p-block atoms in period 3 or later can expand their valence shells due to the empty d-orbitals. I understand this for p-block atoms after period 4 due to the 3d electrons and etc. However, how come the p-block at...
by Brianna Chen 1I
Sat Nov 07, 2020 12:55 am
Forum: Electronegativity
Topic: Periodic Trends
Replies: 9
Views: 38

Periodic Trends

Are there any easy methods that could possibly help me memorize the periodic trends?
by Brianna Chen 1I
Sat Nov 07, 2020 12:52 am
Forum: Ionic & Covalent Bonds
Topic: Formal Charge Equation
Replies: 10
Views: 52

Re: Formal Charge Equation

Since atoms form covalent bonds with each other, they are sharing electrons with each other. Therefore, each bond line can be counted as one electron because we are only taking into consideration one atom which is sharing one electron with another atom (forming the bond line).
by Brianna Chen 1I
Sat Nov 07, 2020 12:48 am
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 10
Views: 33

Re: Resonance Structures

A resonance hybrid is a structure that averages the bond lengths from all of the resonance structures, so it is basically a collective representation of a molecule.
by Brianna Chen 1I
Sat Nov 07, 2020 12:47 am
Forum: Resonance Structures
Topic: resonance structures
Replies: 8
Views: 33

Re: resonance structures

Resonance structures are a group of Lewis structures that collective represent the same molecule but may have different bonding structures. Altogether, resonance structures can be represented by a resonance hybrid which practically averages the bond lengths.
by Brianna Chen 1I
Sat Nov 07, 2020 12:42 am
Forum: Lewis Structures
Topic: lewis structure
Replies: 17
Views: 44

Re: lewis structure

Depending on the charge of the atom or molecule, that will determine which charge goes outside of the brackets. For example, NO3- would be [NO3]- (with the negative charge on the outside of the brackets).
by Brianna Chen 1I
Sat Oct 31, 2020 11:34 pm
Forum: DeBroglie Equation
Topic: Finding the mass of a molecule
Replies: 6
Views: 80

Re: Finding the mass of a molecule

Anytime you see the word "diatomic," you would find the molar mass of two molecules. In this case, it is two Hydrogen molecules (H2). Then, you can use this value in your conversion!
by Brianna Chen 1I
Sat Oct 31, 2020 11:32 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: General Heisenberg Question
Replies: 7
Views: 60

Re: General Heisenberg Question

When dealing with percentages in uncertainty, you would have to take that percentage amount of the value given (not just take the percentage as the uncertainty value). Therefore, you would take 2% of 5.00 for the example you gave which will give you your uncertainty value.
by Brianna Chen 1I
Sat Oct 31, 2020 11:27 pm
Forum: Properties of Light
Topic: Is c always the speed of light?
Replies: 70
Views: 236

Re: Is c always the speed of light?

Yes, so far in this class, we have only learned that c is equal to the speed of light (3.00x10^8 m/s).
by Brianna Chen 1I
Sat Oct 31, 2020 11:26 pm
Forum: Properties of Light
Topic: How to remember what v is in equations
Replies: 46
Views: 138

Re: How to remember what v is in equations

In most cases, velocity deals with a matter that has mass (electrons, neutrons, etc.) whereas frequency deals with wave-like properties, typically found in light. In addition, it is important to keep in mind the conceptual idea behind each equation which will help you understand which equations cont...
by Brianna Chen 1I
Sat Oct 31, 2020 11:24 pm
Forum: Properties of Light
Topic: Relationship between wavelength and frequency
Replies: 10
Views: 70

Re: Relationship between wavelength and frequency

Wavelength and frequency are inversely related to each other because multiplying wavelength and frequency equals to a constant (the speed of light). Therefore, they will always multiply to 3.00x10^8. The higher the frequency, the shorter the wavelength. Likewise, the lower the frequency, the longer ...
by Brianna Chen 1I
Sun Oct 25, 2020 2:05 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Confusion with Uncertainty Values
Replies: 7
Views: 64

Re: Confusion with Uncertainty Values

Uncertainty is mainly about the range of values that the real value could be in. The actual value of the velocity doesn't really matter. For the question you specified, the uncertainty in velocity would be 4 m/s. Thank you for the clarification! I have a better understanding of it now. Do you know ...
by Brianna Chen 1I
Sat Oct 24, 2020 6:13 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: When do we use Heisenberg indeterminacy equation
Replies: 10
Views: 50

Re: When do we use Heisenberg indeterminacy equation

Something you should keep in mind with Heisenberg's Indeterminacy Equation is that the smaller the mass of an object, the more "unknown" or "uncertain" the object's position will be. If we know everything about where a particle is located (the uncertainty of position is small), w...
by Brianna Chen 1I
Sat Oct 24, 2020 6:08 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Confusion with Uncertainty Values
Replies: 7
Views: 64

Confusion with Uncertainty Values

I'm a little confused on the idea of uncertainty. For example, if the problem tells us that the velocity is 14.3 with an uncertainty of +/- 2, would our velocity value just be 4, or would it be 14.3+4?
by Brianna Chen 1I
Sat Oct 24, 2020 6:07 pm
Forum: Properties of Light
Topic: Wavelength
Replies: 14
Views: 61

Re: Wavelength

My TA said that it doesn't matter, but wavelength is usually in units of nanometers. However, since the midterm is multiple choice, this may not be too big of an issue that you have to worry about. Just make sure your value is correct when you convert units!
by Brianna Chen 1I
Sat Oct 24, 2020 6:04 pm
Forum: Properties of Light
Topic: Constants
Replies: 21
Views: 93

Re: Constants

I like to use at least three decimal places, but the more numbers you use, the more accurate your answer will be. If you have a graphing calculator, you can also copy the exact answer and apply it into the equation you are solving for.
by Brianna Chen 1I
Sat Oct 24, 2020 6:02 pm
Forum: *Black Body Radiation
Topic: Midterm
Replies: 14
Views: 208

Re: Midterm

Dr. Lavelle described that a black body is something that absorbs and emits all wavelengths, but this is a topic that is out of the scope of our course, so we do not need to know it for the midterm!
by Brianna Chen 1I
Sat Oct 17, 2020 8:35 pm
Forum: Einstein Equation
Topic: m vs nm
Replies: 66
Views: 359

Re: m vs nm

My TA said that it doesn't matter, but wavelength is typically expressed in nanometers which is why they prefer wavelength to be in units of nm!
by Brianna Chen 1I
Sat Oct 17, 2020 8:32 pm
Forum: Student Social/Study Group
Topic: How do you study?
Replies: 19
Views: 115

Re: How do you study?

I really like doing problems multiple times to really engrain the concepts into my mind, so when I see it on exams (where questions are more difficult), I can sort of piece together how to solve certain problems.
by Brianna Chen 1I
Sat Oct 17, 2020 8:30 pm
Forum: Student Social/Study Group
Topic: Need suggestions on study websites
Replies: 4
Views: 142

Re: Need suggestions on study websites

Like multiple students have already said above, I really like watching Khan Academy because the moderators do a great job of explaining concepts step-by-step. In addition, I like watching Crash Course because it gives me a better understanding of broader concepts such as if you don't know how certai...
by Brianna Chen 1I
Sat Oct 17, 2020 8:26 pm
Forum: Administrative Questions and Class Announcements
Topic: Step Up Sessions
Replies: 71
Views: 4395

Re: Step Up Sessions

Are step up sessions or workshop sessions better for understanding material that may be on exams? Can I still attend workshop sessions if I don't have a strong background in chemistry? Step-up sessions allow you to walk through simpler problems step-by-step where as workshops allow you to engage in...
by Brianna Chen 1I
Sat Oct 17, 2020 8:23 pm
Forum: Student Social/Study Group
Topic: How are you studying?
Replies: 196
Views: 873

Re: How are you studying?

I plan to work through the textbook problems thoroughly in order to gain a better understanding of the concepts (rather than simply memorize them)!
by Brianna Chen 1I
Sat Oct 17, 2020 8:20 pm
Forum: Administrative Questions and Class Announcements
Topic: Where can I buy a webcam for a reasonable price?
Replies: 60
Views: 939

Re: Where can I buy a webcam for a reasonable price?

Amazon is probably your best option, especially with quick shipping and the ability to read customer reviews to determine which webcam is the best. Depending on the quality of the webcam, they usually range from about $15 to $30!
by Brianna Chen 1I
Wed Oct 07, 2020 12:15 am
Forum: Significant Figures
Topic: When are sig figs applied?
Replies: 12
Views: 77

Re: When are sig figs applied?

In this case, should we not round any answers in a multi-step problem until we reach the final answer where we apply the sig fig rule? Also, do you typically round the molar mass of an element from the periodic table? So far, I have been using 1.007 for Hydrogen, 15.999 for Oxygen, etc...but is thi...
by Brianna Chen 1I
Wed Oct 07, 2020 12:11 am
Forum: Significant Figures
Topic: What is the reason why we do not count integers for sig figs?
Replies: 8
Views: 79

Re: What is the reason why we do not count integers for sig figs?

You do count integers for sig figs. Any non-zero integer is a significant figure so both 70 and 80 would have 1 significant figure each while 65 would have 2 because there are 2 non-zero digits. All non-zero digits are significant. Zeroes are only significant if they follow a decimal point or are i...
by Brianna Chen 1I
Wed Oct 07, 2020 12:07 am
Forum: Significant Figures
Topic: When are sig figs applied?
Replies: 12
Views: 77

Re: When are sig figs applied?

In this case, should we not round any answers in a multi-step problem until we reach the final answer where we apply the sig fig rule? Also, do you typically round the molar mass of an element from the periodic table? So far, I have been using 1.007 for Hydrogen, 15.999 for Oxygen, etc...but is this...
by Brianna Chen 1I
Wed Oct 07, 2020 12:03 am
Forum: Significant Figures
Topic: What is the reason why we do not count integers for sig figs?
Replies: 8
Views: 79

What is the reason why we do not count integers for sig figs?

I learned that for integers/exact numbers such as 70 or 80, you do not count the number of sig figs because it is an exact number. Can someone explain this rule to me and the reason why we do not count those sig figs? Does that rule also apply to integers such as 65 and 53 (since these have two sigs...
by Brianna Chen 1I
Wed Oct 07, 2020 12:00 am
Forum: Significant Figures
Topic: How many significant figures are in 7.00 x 10^2?
Replies: 25
Views: 518

Re: How many significant figures are in 7.00 x 10^2?

When dealing with scientific notation, specifically when a number is multiplied by a 10^x, the number of sig figs is counted by the number that appears before the multiplication sign. Therefore, in this case, 7.00 x 10^2 has three significant figures because we only focus on the 7.00 portion of the ...
by Brianna Chen 1I
Tue Oct 06, 2020 11:55 pm
Forum: Administrative Questions and Class Announcements
Topic: Step Up Sessions
Replies: 71
Views: 4395

Re: Step Up Sessions

Regarding step up sessions, do all UAs share the same worksheet or is it recommended to attend multiple sessions because they all focus on different concepts?

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