Search found 30 matches

by TimVintsDis3C
Sat Nov 09, 2019 10:55 pm
Forum: Bond Lengths & Energies
Topic: how to determine the energy of a bond
Replies: 6
Views: 26

Re: how to determine the energy of a bond

Bond Energy can be found by subtracting the sum of all the bonds formed from the sum of all bonds broken.
by TimVintsDis3C
Sat Nov 09, 2019 10:52 pm
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 15
Views: 45

Re: Resonance Structures

Resonance structures are simply alternate Lewis structures for a given ion or molecule.
by TimVintsDis3C
Sat Nov 09, 2019 10:45 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 9
Views: 36

Re: Formal Charge

A formal charge of 0 simply states that a Lewis Structure is at its lowest energy level. Some structures may not have a formal charge of 0, but the goal is to draw a structure so that it is at its lowest formal charge/ more stable.
by TimVintsDis3C
Sat Nov 09, 2019 10:40 pm
Forum: Dipole Moments
Topic: Van Der Waals
Replies: 5
Views: 32

Re: Van Der Waals

Van Der Waals - the weakest interaction and is present in all compounds, something like Iodine and Argong

Dipole-Dipole - stronger, between more positively charged element and negative. An example being Carbon and Oxygen

Hydrogen Bond- strongest, essentially a super bond between H and C,N,O,F
by TimVintsDis3C
Sat Nov 09, 2019 10:37 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Liquid and Solid formation
Replies: 2
Views: 6

Re: Liquid and Solid formation

The balance between the kinetic energies of the molecules and the inter molecular attractions determines whether something will be a solid, liquid, or gas .The attractive forces between the molecules increase as you go down a group so that explains the change.
by TimVintsDis3C
Sun Nov 03, 2019 2:37 pm
Forum: General Science Questions
Topic: Study Tips
Replies: 13
Views: 80

Re: Study Tips

I would do the online modules and go through the problems assigned for homework. I believe all of the questions will be taken from there, so it's almost like an exact study guide.
by TimVintsDis3C
Sun Nov 03, 2019 2:35 pm
Forum: Lewis Structures
Topic: Names
Replies: 4
Views: 29

Re: Names

I doubt it. Unless it is something we learned in class or from our homework. I believe all of the questions will be taken from the homeworks and Online Modules so it will not be something we have never seen before.
by TimVintsDis3C
Sun Nov 03, 2019 2:33 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: electron configuration
Replies: 4
Views: 14

Re: electron configuration

The electrons are removed from the right most sections of the electron configuration. Electrons are typically removed from the valence shells, which are the highest in s and p orbitals.
by TimVintsDis3C
Sun Nov 03, 2019 2:30 pm
Forum: Dipole Moments
Topic: Dipole moments
Replies: 5
Views: 22

Re: Dipole moments

The dipole moment also tells us about the charge. The bigger the difference in electronegativity, the larger the charge and vice versa.
by TimVintsDis3C
Sun Nov 03, 2019 2:27 pm
Forum: Bond Lengths & Energies
Topic: Strength of Bonds
Replies: 16
Views: 37

Re: Strength of Bonds

Shorter Bonds are stronger since the & less reactive, so triple bonds would be the strongest. Longer bonds are weaker and are more likely to be involved in a reaction, so single bonds are the weakest.
by TimVintsDis3C
Sat Oct 26, 2019 11:11 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Lowering Formal Charge
Replies: 6
Views: 36

Re: Lowering Formal Charge

A more stable Lewis structure will have a formal charge of 0. That is why we try to draw the Lewis Structure in different ways to see if we can get the formal charge to 0. In the example provided of (S04^2-), the first Lewis Structure we drew had a final formal charge of (-1); whereas, the second on...
by TimVintsDis3C
Sat Oct 26, 2019 11:07 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic and Covalent Bonds
Replies: 5
Views: 20

Re: Ionic and Covalent Bonds

Ionic compounds transfer dots (electrons) from metal to nonmetal atom.

Non metals do not form cations because their ionization energies are too high sot hey share electrons to form covalent bonds.
by TimVintsDis3C
Sat Oct 26, 2019 11:05 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Shorthand Notation
Replies: 4
Views: 18

Re: Shorthand Notation

My TA let us write the short form of the electron configuration so I believe this is something one of the mods can clarify. Either way its good to know how to do the whole thing.
by TimVintsDis3C
Sat Oct 26, 2019 11:02 pm
Forum: Lewis Structures
Topic: Drawing the Lewis Structure
Replies: 2
Views: 18

Re: Drawing the Lewis Structure

The best way to draw a Lewis Structure is by putting the element with the ionization energy in the middle. This is because all the other atoms will be placed around. You then want to make sure the dots and bonds drawn correlates to the valence electrons calculated from the elements. Also, make sure ...
by TimVintsDis3C
Sat Oct 26, 2019 10:59 pm
Forum: Bond Lengths & Energies
Topic: Bond Lengths
Replies: 4
Views: 26

Re: Bond Lengths

Double bonds and triple bonds have more electrons so they exert a stronger attraction force. This pulls the atoms closer together, creating shorter bond lengths.
by TimVintsDis3C
Sat Oct 19, 2019 7:44 pm
Forum: Empirical & Molecular Formulas
Topic: Molecular to Empirical Formula
Replies: 10
Views: 67

Re: Molecular to Empirical Formula

The Empirical formula is needed to calculate the molecular formula but cannot be done so without the molar mass. Once you have the molar masses of both the Empirical formula and the Molecular formula you divide the two to get the ration. If E(molar mass)/M(molar mass)= 2, then multiply the Empirical...
by TimVintsDis3C
Sat Oct 19, 2019 7:41 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals in relation to arrows
Replies: 10
Views: 58

Re: Orbitals in relation to arrows

Is it possible to have more arrows pointing in one direction than another. If so, what does that entail?
by TimVintsDis3C
Sat Oct 19, 2019 7:38 pm
Forum: Photoelectric Effect
Topic: Work Funtion
Replies: 2
Views: 25

Re: Work Funtion

Both the Work Function and the Threshold Energy function refer to the energy required to eject the electron. They are fundamentally the same when it comes down to calculating. The work function refers to the energy that needs to be put in and the Threshold Energy function refers to the frequency req...
by TimVintsDis3C
Sat Oct 19, 2019 7:34 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg equation [ENDORSED]
Replies: 68
Views: 858

Re: Rydberg equation [ENDORSED]

Are all of these equations meant to be memorized, or will they be provided on tests?
by TimVintsDis3C
Sat Oct 19, 2019 7:30 pm
Forum: Limiting Reactant Calculations
Topic: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]
Replies: 66
Views: 858

Re: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]

I would show all work. I had points taken off my first test for not showing work in some parts. You don't have to show everything step by step, but as long as it shows your calculations you should be fine. If you feel you should have gotten more points for the work you showed you can always talk wit...
by TimVintsDis3C
Tue Oct 08, 2019 12:34 pm
Forum: Limiting Reactant Calculations
Topic: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]
Replies: 66
Views: 858

Re: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]

From what I recall, if you get the answer correct, then you are given full credit as long as some work is shown. However, I would still show work in case I get the problem wrong and my work shown will be worth some partial credit.
by TimVintsDis3C
Tue Oct 08, 2019 12:33 pm
Forum: Balancing Chemical Reactions
Topic: Fractions
Replies: 19
Views: 93

Re: Fractions

I would personally refrain from keeping fractions in the formula because of how easy of a fix it is. All you really have to do is multiply everything by the denominator to remove the fraction. It's an easy fix for something you won't have to worry about later.
by TimVintsDis3C
Tue Oct 08, 2019 12:31 pm
Forum: Empirical & Molecular Formulas
Topic: Limiting Reactants
Replies: 4
Views: 27

Re: Limiting Reactants

Maybe, but if that's the case then it shouldn't be much harder than finding how much product we can make. We would simply find it by using the remaining moles or even by subtracting what we have from the total
by TimVintsDis3C
Tue Oct 08, 2019 12:29 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Word Problem Efficiency
Replies: 7
Views: 58

Re: Word Problem Efficiency

The professor went over this in class and the way he taught us seems to be working fine for me. The steps are as follows: Give yourself time, be mindful What is the question? What concepts do I know? What model or equation do I know? What is known? What is unknown? Can I express the unknown with res...
by TimVintsDis3C
Tue Oct 08, 2019 12:27 pm
Forum: Significant Figures
Topic: How many significant figures are in 7.00 x 10^2?
Replies: 12
Views: 108

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

Sig Figs have to do with any number that isn't a 0 or a 0 between two numbers.
So for example:
72345 has 5 Sig figs
72300 has 3 Sig figs
72032 has 5 sig figs

So in your case there are 3 sig figs.
by TimVintsDis3C
Thu Oct 03, 2019 8:13 pm
Forum: Properties of Light
Topic: EM Spectrum
Replies: 4
Views: 39

Re: EM Spectrum

I'd assume he 'll provide us with a sort of image/ reference. Just how it's ridiculous to have us memorize the periodic table, so he provides us with one on tests. We are learning about the topic and how to find what it is we are looking for, not memorize something that has already been established.
by TimVintsDis3C
Thu Oct 03, 2019 8:10 pm
Forum: Empirical & Molecular Formulas
Topic: Clarification
Replies: 6
Views: 70

Re: Clarification

I'm fairly certain that you can find both if we are given enough information. It's just like how we can find the mass of sample, the number of moles, and the molar mass of the element if we are given at least 2 of these.
by TimVintsDis3C
Thu Oct 03, 2019 8:08 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Determining Molar Mass
Replies: 7
Views: 47

Re: Determining Molar Mass

In most cases it shouldn't matter, but if you require a certain amount of sig figs in your answer, then you would make sure that your answer isn't rounded up too much
by TimVintsDis3C
Thu Oct 03, 2019 8:06 pm
Forum: Student Social/Study Group
Topic: Final Jitters
Replies: 61
Views: 18368

Re: Final Jitters

Personally, I just think of the test on the grand scheme of things. If I know the topic, then I will pass. If I don't , then it is on me to study for the test more rather than worry.
by TimVintsDis3C
Mon Sep 30, 2019 8:23 pm
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student - Part II [ENDORSED]
Replies: 117
Views: 1533

Re: Advice from a Medical Student - Part II [ENDORSED]

I was wondering what it takes to get into med school. I know the expectations were high to get into UCLA in the 1st place and was wondering how much harder does it get?

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