Search found 31 matches

by Savannah Torella 1L
Sun Nov 15, 2020 6:06 pm
Forum: Ionic & Covalent Bonds
Topic: Sapling Q: Hydrogen Bonds
Replies: 7
Views: 27

Re: Sapling Q: Hydrogen Bonds

Molecules that are highly electronegative are N,O, and F, which means these are the atoms that can form hydrogen bonds. Carbon couldn't form a hydrogen bond because it's electronegativity is too close to hydrogen's.
by Savannah Torella 1L
Sun Nov 15, 2020 5:59 pm
Forum: Bond Lengths & Energies
Topic: Interaction Potential Energy
Replies: 2
Views: 24

Interaction Potential Energy

Can someone explain what the interaction potential energy equation would be used for and what this equation is composed of?
by Savannah Torella 1L
Sun Nov 15, 2020 5:47 pm
Forum: Lewis Structures
Topic: Nitrate Ion Lewis Structure
Replies: 6
Views: 26

Re: Nitrate Ion Lewis Structure

The nitrate ion has a +1 charge because on the periodic table, you can see that nitrogen has 5 valence electrons. However in nitrate, nitrogen is only connected the 4 electrons, sharing two from a double bond with oxygen and sharing two from 2 single bonds with O. Since the nitrogen atom is missing ...
by Savannah Torella 1L
Sun Nov 15, 2020 5:30 pm
Forum: Resonance Structures
Topic: bond length
Replies: 37
Views: 74

Re: bond length

We do not need to know how to calculate for bond lengths. In lectures, Dr. Lavelle told us that the values given to us were ones that he looked up, meaning that we wouldn't be expected to find them ourselves. All you need to know is that the bonds from longest to shortest are single, double, triple ...
by Savannah Torella 1L
Sun Nov 15, 2020 5:25 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic vs Atomic Radius
Replies: 7
Views: 30

Re: Ionic vs Atomic Radius

The atomic radius is the distance between the nucleus and the element's normal valence electrons, while the ionic radius is the distance between the nucleus and the outermost valence electron of the ion. The ionic radius of a positive ion is smaller than the atomic radius of the element, while the i...
by Savannah Torella 1L
Sun Nov 08, 2020 7:44 pm
Forum: Resonance Structures
Topic: Delocalized Electrons
Replies: 3
Views: 15

Delocalized Electrons

In Lavelle's lecture, he mentioned that electrons involved in resonance structures are delocalized. I was just wondering what delocalized meant for an electron.
by Savannah Torella 1L
Sun Nov 08, 2020 7:38 pm
Forum: Lewis Structures
Topic: Lewis Dot Structure
Replies: 11
Views: 31

Lewis Dot Structure

When drawing a Lewis dot structure for an element, does it matter which order you place the dots in? I thought I remembered there being a specific order in high school, but it doesn't seem to be mentioned now.
by Savannah Torella 1L
Sun Nov 08, 2020 7:23 pm
Forum: Resonance Structures
Topic: Question about Resonance Def
Replies: 5
Views: 18

Re: Question about Resonance Def

In simple terms, resonance is when a Lewis structure can show more than just simple bonds, ie double or triple bonds, and that these bonds can be placed anywhere on the structure and still make the structure true. For example, for NO3- a double bond can be placed between any N and O, as long as one ...
by Savannah Torella 1L
Sun Nov 08, 2020 7:17 pm
Forum: Ionic & Covalent Bonds
Topic: Size of Bonds
Replies: 28
Views: 92

Re: Size of Bonds

Double bonds are shorter than single bonds because they contain more electrons. When an anion contains a large amount of electrons, that means that it can be more easily pulled into a cation. When the two are easily pulled into each other, that results in a shorter bond length.
by Savannah Torella 1L
Sun Nov 08, 2020 7:05 pm
Forum: Trends in The Periodic Table
Topic: Octet Rule
Replies: 6
Views: 27

Re: Octet Rule

As mentioned above, H, He, Li, and Be are exceptions to the octet rule because they only consist of the s-orbital. Since H and He only contain the 1s orbital, and Li and Be only contain the 1s and 2s orbitals, none of these elements can hold 8 valence electrons. Without containing the p orbitals, th...
by Savannah Torella 1L
Sun Nov 01, 2020 9:53 pm
Forum: Trends in The Periodic Table
Topic: Sapling Question (Radius)
Replies: 10
Views: 43

Re: Sapling Question (Radius)

As, fellow students above have mentioned, cations are always smaller than their parent atom, and anions are always larger than their parent atom. That means for any element given, the radius size from largest to smallest would be Cs-,Cs,Cs+.
by Savannah Torella 1L
Sun Nov 01, 2020 9:47 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Sapling Week 2-4 #21
Replies: 4
Views: 23

Sapling Week 2-4 #21

I was having trouble figuring out how many electrons could have the set of quantum numbers n=5, l=2. I eventually discovered the answer was 10 but I was wondering if somebody could explain why that is.
by Savannah Torella 1L
Sun Nov 01, 2020 9:44 pm
Forum: *Shrodinger Equation
Topic: Schrodinger Equation
Replies: 4
Views: 25

Schrodinger Equation

I was just wondering if anyone had an example of a word problem where the Schrodinger equation would be used. I'm having trouble understanding its application to current questions we have been approaching.
by Savannah Torella 1L
Sun Nov 01, 2020 9:40 pm
Forum: DeBroglie Equation
Topic: Units for DeBrogile Equation
Replies: 5
Views: 22

Units for DeBrogile Equation

What are all the units that should be used when a value is being calculated with the DeBrogile equation? I kept mixing my units up during Sapling problems.
by Savannah Torella 1L
Sun Nov 01, 2020 9:37 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Avogadro constant
Replies: 12
Views: 55

Avogadro constant

When do you want to use the Avogadro constant? How are you able to tell when it is needed?
by Savannah Torella 1L
Sun Oct 25, 2020 11:03 pm
Forum: DeBroglie Equation
Topic: Determining Energy of a Photon
Replies: 5
Views: 45

Re: Determining Energy of a Photon

Yes, 2.5 micrometers should be used as the wavelength. Just make sure you convert micrometers into meters first!
by Savannah Torella 1L
Sun Oct 25, 2020 10:55 pm
Forum: Properties of Light
Topic: Units for wavelength/frequency
Replies: 18
Views: 84

Re: Units for wavelength/frequency

Wavelength is usually measured in meters, while frequency is usually measured in Hz or s^-1. However, I have seen nm used a lot on Sapling problems, so I think it would be beneficial to know how to convert between the two. Nanometer is 10^-9, so to go from nanometer to meter you would move 9 spaces ...
by Savannah Torella 1L
Sun Oct 25, 2020 10:16 pm
Forum: Properties of Light
Topic: Work function
Replies: 5
Views: 27

Work function

How do you know when you are finding the normal energy versus the threshold energy? I am still a little confused by that.
by Savannah Torella 1L
Sun Oct 25, 2020 10:12 pm
Forum: Properties of Light
Topic: Is c always the speed of light?
Replies: 70
Views: 232

Is c always the speed of light?

When using the equation E= hc/ wavelength, is c always going to be the speed of light constant? Are there any instances were c is a different variable?
by Savannah Torella 1L
Sun Oct 25, 2020 10:01 pm
Forum: DeBroglie Equation
Topic: De Broglie's Equation vs C=wavelength(v)
Replies: 8
Views: 48

Re: De Broglie's Equation vs C=wavelength(v)

Although both of these equations involve the variable v, the v stands for different things in each each. In De Broglie's Equation, the v stands for speed/ velocity. In c= wavelength(v), v stands for frequency. This means that if the problem involves speed, you use De Broglie, and if the problem invo...
by Savannah Torella 1L
Sun Oct 18, 2020 10:45 pm
Forum: SI Units, Unit Conversions
Topic: Metric Conversions
Replies: 9
Views: 109

Re: Metric Conversions

Could someone explain the way to use this acronym? How many times you move the decimal places moving up or down, I am a little rusty on it. In addition, what is the "middle" starting point? When using the acronym "King Henry Died By Drinking Chocolate Milk," the starting point i...
by Savannah Torella 1L
Sun Oct 18, 2020 10:27 pm
Forum: Quantum Numbers and The H-Atom
Topic: Why are the numbers backwards on the Lyman and Balmer Model?
Replies: 2
Views: 25

Re: Why are the numbers backwards on the Lyman and Balmer Model?

If you are talking about the model that was given during the presentation, which I'm pretty sure you are, it's because this graph is based off each specific energy level. Under the Lyman series, it is showing that the electron can jump between levels ranging between the first energy level and the si...
by Savannah Torella 1L
Sun Oct 18, 2020 10:14 pm
Forum: Student Social/Study Group
Topic: Forming Virtual Study Group
Replies: 31
Views: 135

Re: Forming Virtual Study Group

I would definitely be interested! My email is storella@ucla.edu if you ever need to contact me about studying.
by Savannah Torella 1L
Sun Oct 18, 2020 10:01 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration
Replies: 8
Views: 319

Re: Electron Configuration

When it comes to electron configuration, you want to write the orbitals in the order that they were fully filled. In the context of your question, 3d would be written before the 4s since the 3d orbital is filled up first between the two.
by Savannah Torella 1L
Sun Oct 18, 2020 9:57 pm
Forum: Properties of Electrons
Topic: protons and electrons
Replies: 33
Views: 177

Re: protons and electrons

I think a few people have answered this, but protons and neutrons have similar masses. This is why the atomic mass is determined by the amount of both protons and neutrons.However, electrons are drastically smaller in comparison to protons and neutrons. They are so small that their weight is not inc...
by Savannah Torella 1L
Sun Oct 11, 2020 10:08 pm
Forum: Empirical & Molecular Formulas
Topic: Sapling Week 1 #8
Replies: 23
Views: 179

Re: Sapling Week 1 #8

I know that this picture can look very overwhelming at first, but don't be discouraged. When using the picture, you do not need to pay attention to the different kinds of bonds formed. Whether it is a single bond or a double bond, it does not effect the molecular formula or mass. All you need to do ...
by Savannah Torella 1L
Sun Oct 11, 2020 9:58 pm
Forum: Balancing Chemical Reactions
Topic: Molar Mass
Replies: 23
Views: 137

Re: Molar Mass

Usually while calculating, I use all of the decimals given on the periodic table. I don't know how different it is for every table, but mine has three number after the decimal point. I use all of those decimal until the very end. I then round my answer by the same amount of decimal places given to o...
by Savannah Torella 1L
Sun Oct 11, 2020 9:48 pm
Forum: Molarity, Solutions, Dilutions
Topic: Sapling HW #6
Replies: 8
Views: 65

Re: Sapling HW #6

I think you may have calculated the molar mass of CuNO3 incorrectly. Using the periodic table, 63.546+14.007+(3*15.999)= 125.55gmol^-1. Hope that helps!
by Savannah Torella 1L
Sun Oct 11, 2020 9:33 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Combustion Reactions
Replies: 6
Views: 73

Re: Balancing Combustion Reactions

From my past learnings, this is indeed the case. When there is a combustion, that means that oxygen and heat is involved. With hydrocarbon compounds, H2O and CO2 are produced. So I think it's safe to say that + O2 -> H2O + CO2 is always used for combustion reactions. Although, I think there are occa...
by Savannah Torella 1L
Sun Oct 11, 2020 9:16 pm
Forum: Molarity, Solutions, Dilutions
Topic: Sapling HW Number 7
Replies: 12
Views: 118

Re: Sapling HW Number 7

For number 7, you are trying to find the mass/moles of the solute(n), and you are given the mass percentage of CaCl2. With the mass percentage, you can divide that number by 100 to get the molarity of CaCl2. After finding the volume of the solution (using the periodic table), you can plug M and v in...
by Savannah Torella 1L
Mon Oct 05, 2020 10:20 am
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student [ENDORSED]
Replies: 221
Views: 115843

Re: Advice from a Medical Student [ENDORSED]

This is very helpful thank you for your perspective! I am one who always keep my notes but never end up using them, so it is encouraging to know that these notes helped you with future classes.

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