Search found 34 matches

by Kelsey Li 3B
Sat Dec 08, 2018 2:50 pm
Forum: Administrative Questions and Class Announcements
Topic: Final
Replies: 11
Views: 367

Re: Final

The final will cover everything from the beginning to acids & bases but we are focusing on the strong acids and bases. The final will be 8 questions long just like the midterm.
by Kelsey Li 3B
Sat Dec 08, 2018 2:49 pm
Forum: Biological Examples
Topic: What should we know for the final?
Replies: 6
Views: 312

Re: What should we know for the final?

I agree with knowing about cisplatin especially because it was an example on the churro practice exam.
by Kelsey Li 3B
Sat Dec 08, 2018 2:48 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shape
Replies: 5
Views: 152

Re: Shape

When we are asked for the shape then we respond with the molecular geometry, not the electronic geometry.
by Kelsey Li 3B
Sun Dec 02, 2018 11:14 pm
Forum: Hybridization
Topic: Double and Triple Bonds
Replies: 17
Views: 270

Re: Double and Triple Bonds

Double and triple bonds do not change the hybridization of an atom. It only changes with the amount of electron densities.
by Kelsey Li 3B
Sun Dec 02, 2018 11:13 pm
Forum: Hybridization
Topic: hybridization
Replies: 13
Views: 424

Re: hybridization

You should draw the Lewis structure first then count the electron densities. What I also do is I look at the shape that the central atom is a part of and determine its hybridization from it.
by Kelsey Li 3B
Sun Dec 02, 2018 11:12 pm
Forum: Hybridization
Topic: Sigma bonds
Replies: 9
Views: 158

Re: Sigma bonds

Every bond in a molecule is considered a sigma bond. But bonds on top of those are considered pi bonds.
by Kelsey Li 3B
Sun Dec 02, 2018 11:11 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Notation
Replies: 10
Views: 164

Re: VSEPR Notation

The AXE notation is on the exam and it will probably be the same on the final.
by Kelsey Li 3B
Sun Dec 02, 2018 11:10 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Seesaw
Replies: 13
Views: 347

Re: Seesaw

The bond angles for seesaw is <90 and <120 degrees,
by Kelsey Li 3B
Sun Dec 02, 2018 11:09 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent vs angular?
Replies: 15
Views: 245

Re: Bent vs angular?

Bent and angular are the same shape,
by Kelsey Li 3B
Sun Nov 25, 2018 3:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: How to state bond angles.
Replies: 7
Views: 161

Re: How to state bond angles.

You don't need to know the exact bond angle but you should know something along the lines of less than 109.5 degrees if you don't know the specifics.
by Kelsey Li 3B
Sun Nov 25, 2018 3:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shapes Not covered in Lecture
Replies: 10
Views: 203

Re: Shapes Not covered in Lecture

Because T-shaped came up in some homework problems, I would just know the shape in case it were to come up on the test.
by Kelsey Li 3B
Sun Nov 25, 2018 3:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polarity
Replies: 6
Views: 101

Re: Polarity

A VSEPR model shape is not always polar. Polarity depends on the symmetry of the molecule and even if the molecule has lone pairs, it doesn't have to be polar because lone pairs can cancel out.
by Kelsey Li 3B
Sat Nov 10, 2018 11:13 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Atom Distance, repulsion?
Replies: 6
Views: 254

Re: Atom Distance, repulsion?

The significance of the bonds being as far as apart from each other is to explain that the molecule is most stable when electrons are far away from each other as possible and this is because their negative charges repel each other.
by Kelsey Li 3B
Sat Nov 10, 2018 11:12 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Double bond
Replies: 5
Views: 289

Re: Double bond

To figure out the length of the bond, you look at the amount of bonded electrons. The higher the bonded electrons, the stronger the pull between the two atoms which means a shorter bond length.
by Kelsey Li 3B
Sat Nov 10, 2018 11:11 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Isoelectronic
Replies: 14
Views: 569

Re: Isoelectronic

Isoelectronic means that the two atoms have the same number of valence electrons
by Kelsey Li 3B
Sat Nov 10, 2018 11:08 pm
Forum: Hybridization
Topic: Bond types
Replies: 4
Views: 214

Re: Bond types

Hydrogen bonds occur when an O,N or F atom that has a lone pair interacts with the H that is bonded to another N,O or F atom. Polar covalent bonds occur when a pair of electrons aren't equally shared between atoms and it's from one atom having a higher electronegativity than the other Non polar cova...
by Kelsey Li 3B
Sat Nov 10, 2018 11:02 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Hydrogen Bonding
Replies: 2
Views: 49

Re: Hydrogen Bonding

Hydrogen bonds happen between molecules.
by Kelsey Li 3B
Sat Nov 10, 2018 10:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape
Replies: 2
Views: 59

Re: Molecular Shape

If it is a linear shape, the two atoms on either side of the central atom doesn't have to be the same element.
by Kelsey Li 3B
Fri Nov 02, 2018 12:10 pm
Forum: DeBroglie Equation
Topic: Momentum
Replies: 10
Views: 509

Re: Momentum

If the momentum isn't given, you just solve for momentum with the equation p = mv where m is the mass (kg) and v is the velocity (m/s)
by Kelsey Li 3B
Fri Nov 02, 2018 12:09 pm
Forum: Lewis Structures
Topic: Drawing Lewis Structures
Replies: 14
Views: 353

Re: Drawing Lewis Structures

Since we didn't learn the VESPR orientation yet I don't think we need to worry about bond angles. What's most important is just making sure when you draw your lewis dot structure that it's drawn evenly. The lewis dot structure just represent where the electrons are and the type of bonds but we don't...
by Kelsey Li 3B
Fri Nov 02, 2018 12:06 pm
Forum: Student Social/Study Group
Topic: Midterm
Replies: 15
Views: 444

Re: Midterm

I think it's around 8 questions but there will be multiple parts to it (a,b,c,d,e) and we will have just two hours to solve them all. Hopefully we have enough time to be able to finish and review our answers.
by Kelsey Li 3B
Sun Oct 28, 2018 9:49 am
Forum: Lewis Structures
Topic: Electron Configuration
Replies: 4
Views: 119

Re: Electron Configuration

The S, p, d, and f symbols represent the angular momentum number and orbitals
s, l=0; p, l=1; d, l=2; f, l=3
An example is 5p, n = 5 and l =1
by Kelsey Li 3B
Sun Oct 28, 2018 9:45 am
Forum: Ionic & Covalent Bonds
Topic: Bond
Replies: 9
Views: 212

Re: Bond

Quadruple bonds are extremely rare so I don't think for this class we need to worry about it.
by Kelsey Li 3B
Sun Oct 28, 2018 9:44 am
Forum: Ionic & Covalent Bonds
Topic: Electron Affinity vs. Ionization Energy [ENDORSED]
Replies: 4
Views: 65

Re: Electron Affinity vs. Ionization Energy [ENDORSED]

The ionization energy is the energy required to remove an electron from a neutral atom whereas the electron affinity is the energy change when a neutral atom attracts an electron.
by Kelsey Li 3B
Fri Oct 19, 2018 4:18 am
Forum: Quantum Numbers and The H-Atom
Topic: Quantum Number L [ENDORSED]
Replies: 3
Views: 93

Re: Quantum Number L [ENDORSED]

The quantum number L represents the orbital angular momentum which is the shape of the orbital. l is typically n-1 where n is a whole number integer from 1-7.
L values correspond with the shape of the orbital (s,p,d,f). When l=0 it is s. When l=1, it is p. When l=2, it is d. When l=3, it is f.
by Kelsey Li 3B
Fri Oct 19, 2018 4:04 am
Forum: Trends in The Periodic Table
Topic: s, p, d, f
Replies: 16
Views: 402

Re: s, p, d, f

The difference between the orbitals of s,p,d, and f is the shape of the orbital. Within these orbitals are subshells and s=1, p=3, d=5, and f=7.
by Kelsey Li 3B
Fri Oct 19, 2018 3:48 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Quantum numbers, shells, subshells
Replies: 2
Views: 49

Re: Quantum numbers, shells, subshells

n stands for the principle quantum number and is categorized by whole number integers ranging from 1-7 l stands for the angular momentum number and describes the shape of the orbital(s, p, d, f) and is usually an integer of n-1 ml stands for the magnetic quantum number and describes the 3d orientati...
by Kelsey Li 3B
Sat Oct 13, 2018 7:01 pm
Forum: Properties of Electrons
Topic: wavelength and ounces
Replies: 4
Views: 121

Re: wavelength and ounces

I would first convert the speed and mass. I would change 92mph to m/s which is 41 m/s and the 5.51 ounce to kg which is 0.146 kg.
Then use De Broglie's equation, λ = h / mv = ( 6.64 x 10^-34 J-s ) / ( .146 kg ) ( 41 m/s ) which will give you λ = 1.1 x 10^-34 m.
Hope this helps (:
by Kelsey Li 3B
Sat Oct 13, 2018 6:57 pm
Forum: Properties of Light
Topic: Wavelength Units
Replies: 5
Views: 92

Re: Wavelength Units

Since wavelengths are so small, using nanometers would better suit the answer in units. However, when you are solving the problem I would suggest sticking to meters or at least the same unit throughout so you don't have any complications. Just like what 804991762_4A said, you can convert meters to n...
by Kelsey Li 3B
Sat Oct 13, 2018 6:55 pm
Forum: Properties of Light
Topic: De Brogile Equation
Replies: 6
Views: 58

Re: De Brogile Equation

As we talked in class, De Brogile Equation is λ = h / (mass x velocity) and this is just used to measure the wavelength of moving particles. H represents Planck's Constant which is 6.626 × 10^-34 m^2 kg/s. Also remember to make sure all units are the same so that it cancels correctly. This equation ...
by Kelsey Li 3B
Sat Oct 06, 2018 2:08 pm
Forum: Significant Figures
Topic: Rounding numbers ending in 5
Replies: 9
Views: 155

Re: Rounding numbers ending in 5

I would continue to go with what you were taught with in the fact that you should round up if you have a number ending with 5. Therefore if it was 2.65 I would round it to 2.7 still. If you are still really unsure I would go ask a TA but I'm sure they'll tell you that it's okay to round up! Hope thi...
by Kelsey Li 3B
Sat Oct 06, 2018 2:04 pm
Forum: General Science Questions
Topic: Rusty on High School Chem [ENDORSED]
Replies: 166
Views: 100980

Re: Rusty on High School Chem [ENDORSED]

I took AP Chemistry my Junior year in highschool and I feel like I've definitely forgotten a lot of things. However, working on the modules and the practice problems that Professor Lavelle assigned will do a great amount of help. Just like what others said, there are other websites that can help cla...
by Kelsey Li 3B
Sat Oct 06, 2018 1:58 pm
Forum: SI Units, Unit Conversions
Topic: Formula Units?
Replies: 3
Views: 77

Re: Formula Units?

Formula units refer to the concept that one mole contains the Avogadro's number of any units. This means that one moles is equal to 6.022*10^23 formula units which is also equivalent to 6.022*10^23 molecules. Formula units just refer to ionic compounds while molecules refer to molecular compounds. H...

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