Search found 50 matches
- Sat Dec 07, 2019 3:23 pm
- Forum: Naming
- Topic: Transition Metal Latin Names
- Replies: 3
- Views: 903
Re: Transition Metal Latin Names
iron and copper
- Sun Dec 01, 2019 12:31 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: dipole-dipole in a solid phase vs gas phase
- Replies: 15
- Views: 1120
Re: dipole-dipole in a solid phase vs gas phase
Solid phase
- Sun Dec 01, 2019 12:30 am
- Forum: Student Social/Study Group
- Topic: Test 2 and Final
- Replies: 18
- Views: 858
Re: Test 2 and Final
My TA gave me my test before thanksgiving and the final should be cumulative
- Sun Dec 01, 2019 12:28 am
- Forum: Administrative Questions and Class Announcements
- Topic: Difficulty
- Replies: 14
- Views: 822
Re: Difficulty
Despite taking AP chem, this call has still been difficult. It covers topics more in depth than what I learnt in high school.
- Sun Dec 01, 2019 12:27 am
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Sigma and Pi Bonds
- Replies: 12
- Views: 1023
Re: Sigma and Pi Bonds
1 sigma and 2 pi bonds
- Sun Dec 01, 2019 12:25 am
- Forum: Student Social/Study Group
- Topic: Final Preparation
- Replies: 2
- Views: 188
Re: Final Preparation
It should be everything we’ve learnt this quarter
- Sun Dec 01, 2019 12:23 am
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam Content
- Replies: 14
- Views: 738
Re: Final Exam Content
Cumulative!
- Sun Dec 01, 2019 12:22 am
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2 Grades
- Replies: 10
- Views: 626
Re: Test 2 Grades
They’re on MyUcla and my TA gave them back during my discussion before thanksgiving
- Sun Dec 01, 2019 12:21 am
- Forum: Student Social/Study Group
- Topic: Preparing for the final
- Replies: 25
- Views: 1166
Re: Preparing for the final
The TA review sessions and reading the textbook helped a lot for me!
- Sun Nov 24, 2019 10:38 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bent vs linear
- Replies: 56
- Views: 4032
Re: Bent vs linear
bent has a lone pair while linear does not
- Thu Nov 21, 2019 3:10 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: dipole-dipole in a solid phase vs gas phase
- Replies: 15
- Views: 1120
Re: dipole-dipole in a solid phase vs gas phase
Dipole-dipole in the solid phase
- Thu Nov 21, 2019 3:10 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: test 2
- Replies: 3
- Views: 265
Re: test 2
^ retweet
- Thu Nov 21, 2019 3:07 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bent vs linear
- Replies: 56
- Views: 4032
Re: Bent vs linear
Bent has a lone pair while linear does not.
- Thu Nov 21, 2019 3:05 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Boiling Points and IMF Strength
- Replies: 6
- Views: 442
Re: Boiling Points and IMF Strength
As IMF increases in strength then the boiling point/melting point increases in order to break them
- Thu Nov 21, 2019 3:04 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: tetrahedral vs. trigonal pyramidal
- Replies: 4
- Views: 357
Re: tetrahedral vs. trigonal pyramidal
They are not the same. They both have four regions of electron density. However, tetrahedral has zero lone pairs which tribal pyramidal has one lone pair.
- Thu Nov 21, 2019 3:00 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: electron-pair geometry vs molecular geometry
- Replies: 3
- Views: 224
Re: electron-pair geometry vs molecular geometry
Electron pair geometry: number of regions of electron density
Molecular geometry: includes bonding pairs and lone pairs.
Molecular geometry: includes bonding pairs and lone pairs.
- Sat Nov 16, 2019 3:49 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: T Shape
- Replies: 7
- Views: 497
Re: T Shape
It'll be safe to memorize them all
- Sat Nov 16, 2019 3:48 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Sulfite Ion example in class
- Replies: 6
- Views: 443
Re: Sulfite Ion example in class
The lone pair creates an electron electron repulsion. Therefore, it'll push the bonded atoms away from it but push them closer to each other.
- Sat Nov 16, 2019 3:45 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Drawing Molecular Structures
- Replies: 8
- Views: 494
Re: Drawing Molecular Structures
Lavelle said to just know how to name them.
- Sat Nov 16, 2019 3:43 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR
- Replies: 3
- Views: 221
Re: VSEPR
I just follow this chart!
- Sat Nov 16, 2019 3:41 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Test Topics
- Replies: 11
- Views: 717
Re: Test Topics
It should be everything after 2D!
- Sun Nov 10, 2019 3:33 pm
- Forum: Bond Lengths & Energies
- Topic: Strongest Bond
- Replies: 15
- Views: 7154
Re: Strongest Bond
strongest to weakest is: covalent, ionic, hydrogen, dipole-dipole, london dispersion forces.
Bonds are stronger when they are shorter and have a higher bond order too.
Bonds are stronger when they are shorter and have a higher bond order too.
- Sun Nov 10, 2019 3:32 pm
- Forum: Trends in The Periodic Table
- Topic: atomic radius
- Replies: 7
- Views: 512
Re: atomic radius
It decreases across the periodic table because there are more protons so there’s a strong nuclear charge pull.
- Sun Nov 10, 2019 3:31 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2
- Replies: 7
- Views: 424
Re: Test 2
It should pick up from after 2D
- Sun Nov 10, 2019 3:30 pm
- Forum: Electronegativity
- Topic: Periodic Trend
- Replies: 13
- Views: 734
Re: Periodic Trend
Electronegativity increases up groups then across periods.
- Sun Nov 10, 2019 3:26 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Quantum numbers
- Replies: 12
- Views: 707
Re: Quantum numbers
The angular momentum is the l.
- Thu Oct 31, 2019 6:55 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm
- Replies: 16
- Views: 669
Re: Midterm
Yes, everything up to 2D!
- Thu Oct 31, 2019 6:54 pm
- Forum: Electronegativity
- Topic: Electronegativity
- Replies: 11
- Views: 555
Re: Electronegativity
It is how strongly an atom will attract electrons. So as you go across the period increase and as you go down a group it decreases.
- Thu Oct 31, 2019 6:50 pm
- Forum: DeBroglie Equation
- Topic: When to use the de Broglie equation?
- Replies: 5
- Views: 271
Re: When to use the de Broglie equation?
Whenever there is a mass given.
The equation E=hv and c=(wavelength)v would be specifically for light since c is used.
The equation E=hv and c=(wavelength)v would be specifically for light since c is used.
- Thu Oct 31, 2019 6:47 pm
- Forum: Ionic & Covalent Bonds
- Topic: Chemical Formula by expected charges
- Replies: 2
- Views: 109
Re: Chemical Formula by expected charges
If you look up periodic table charges on Google images, it shows the charges per group (it's easy to remember). So Mg has a charge of +2 and As has a charge of -3. Therefore it would be Mg3As2.
- Thu Oct 31, 2019 6:41 pm
- Forum: Properties of Electrons
- Topic: Atomic Spectra
- Replies: 2
- Views: 209
Re: Atomic Spectra
During the midterm review session, she said we most likely don't need to memorize it but just to somewhat know visible light and gamma rays (if I remember correctly).
- Sun Oct 27, 2019 12:50 am
- Forum: Trends in The Periodic Table
- Topic: atomic Radii
- Replies: 11
- Views: 399
Re: atomic Radii
yes! the more electrons means a larger radii because there will essentially be more shells.
- Sun Oct 27, 2019 12:47 am
- Forum: Ionic & Covalent Bonds
- Topic: Resonance
- Replies: 12
- Views: 414
Re: Resonance
Resonance involves delocalized electrons. That means fewer repulsions and more stability with a larger volume.
- Sun Oct 27, 2019 12:46 am
- Forum: Ionic & Covalent Bonds
- Topic: How are lewis structures filled?
- Replies: 6
- Views: 204
Re: How are lewis structures filled?
The first thing is that the atoms must follow the octet rule. Distribute the electrons one by one
- Sun Oct 27, 2019 12:45 am
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm
- Replies: 11
- Views: 501
Re: Midterm
November 6th! As for the format it should be like the last test?
- Sun Oct 27, 2019 12:45 am
- Forum: Ionic & Covalent Bonds
- Topic: Cation
- Replies: 23
- Views: 1615
Re: Cation
Cations are atoms lost an electron so it has a positive charge.Anions are atoms that have gained an electron so it has a negative charge.
They're important because some elements are more stable as ions because they can gain their octet by gaining or losing an electron.
They're important because some elements are more stable as ions because they can gain their octet by gaining or losing an electron.
- Thu Oct 17, 2019 2:28 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: What is Molarity?
- Replies: 11
- Views: 957
Re: What is Molarity?
Molarity is moles per liters, referring to the concentration of atoms/molecules in a solvent.
- Thu Oct 17, 2019 2:27 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: how to express answer
- Replies: 6
- Views: 151
Re: how to express answer
In class, Prof Lavelle ended with a = sigg. I'm pretty sure he said it was just simpler than writing greater than or equal to.
- Thu Oct 17, 2019 2:23 pm
- Forum: Properties of Light
- Topic: Speed of light
- Replies: 13
- Views: 344
Re: Speed of light
Electromagnetic radiation moves at the speed of light
Because the calc is about a type of light, c= 3x10^-8 m/s is used.
Because the calc is about a type of light, c= 3x10^-8 m/s is used.
- Thu Oct 17, 2019 2:19 pm
- Forum: DeBroglie Equation
- Topic: De Broglie's Equation
- Replies: 17
- Views: 547
Re: De Broglie's Equation
De Broglie's equation requires an object to have a mass
wavelength = h/mv
wavelength = h/mv
- Thu Oct 17, 2019 2:16 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Spin State
- Replies: 17
- Views: 365
Re: Spin State
Spinning up is positive (+1/2)
Spinning down is negative -1/2
Spinning down is negative -1/2
- Fri Oct 11, 2019 2:47 pm
- Forum: Student Social/Study Group
- Topic: Study Tips
- Replies: 58
- Views: 4293
Re: Study Tips
I personally read the textbook and take notes before lectures so the ideas will be explained again in different rooms. Whenever I have other questions I come to chemistry community and there are usually people who are having the same questions!
- Fri Oct 11, 2019 2:45 pm
- Forum: Significant Figures
- Topic: Sig Figs in % Yield
- Replies: 10
- Views: 6436
Re: Sig Figs in % Yield
It would round up toe 64%, the next whole number
- Fri Oct 11, 2019 2:42 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Accuracy and Precision
- Replies: 8
- Views: 400
Re: Accuracy and Precision
It will usually apply to when you do labs or collect data.
Accuracy is how close your data is to the true value while precision is how close your data is to each other. Your data can be precise but not accurate.
Accuracy is how close your data is to the true value while precision is how close your data is to each other. Your data can be precise but not accurate.
- Fri Oct 11, 2019 2:40 pm
- Forum: Significant Figures
- Topic: Sig Figs in Answer
- Replies: 8
- Views: 416
Re: Sig Figs in Answer
For calculating mass % I usually do four sig figs ex: 56.78%
For molar mass I would do four sig figs after the decimal points ex; 12.3456
For molar mass I would do four sig figs after the decimal points ex; 12.3456
- Tue Oct 01, 2019 11:08 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: HW E9 Part B
- Replies: 4
- Views: 265
Re: HW E9 Part B
1. you need to find the amount of moles in 5.51g.
- you divide 5.51g by the molar mass of the compound, 24.48
2. multiply by Avogadro's constant (6.022 x 10^23)
- the units of moles will cancel out and you are left with formula units!
- you divide 5.51g by the molar mass of the compound, 24.48
2. multiply by Avogadro's constant (6.022 x 10^23)
- the units of moles will cancel out and you are left with formula units!
- Tue Oct 01, 2019 11:05 pm
- Forum: Significant Figures
- Topic: Rounding the elements
- Replies: 12
- Views: 798
Re: Rounding the elements
I typically use the exact numbers that are given on the periodic table. This can prevent your answer from being a little off.
- Tue Oct 01, 2019 11:01 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Avogadro's Number [ENDORSED]
- Replies: 12
- Views: 779
Re: Avogadro's Number [ENDORSED]
When you want to convert from moles to atoms, you multiply the molar amount by Avogadro’s number.
When you want to convert from atoms to moles, divide the atom amount by Avogadro’s number.
When you want to convert from atoms to moles, divide the atom amount by Avogadro’s number.
- Tue Oct 01, 2019 10:54 pm
- Forum: Significant Figures
- Topic: E1 Sig Figs
- Replies: 4
- Views: 230
Re: E1 Sig Figs
When trying to figure out sig figs, you should always look at the original question to figure out how many sig figs will be in your answer. In your example, there were the numbers 1.00 mol Ag atoms and the number 144 pm. Both of those numbers have 3 sig figs. The answer would not be 2 x 10^14 becaus...
- Tue Oct 01, 2019 10:50 pm
- Forum: Significant Figures
- Topic: Sig Figs in homework problems
- Replies: 4
- Views: 158
Re: Sig Figs in homework problems
For example, the problem had the numbers 3.45g and 100.79 g.
You should base the number of sig figs on the original problem. Even if you used a the atomic mass of 1.008 for hydrogen in your calculations, the sig figs should be based on 3.45g (3 sig figs) not 100.79 or 1.008.
You should base the number of sig figs on the original problem. Even if you used a the atomic mass of 1.008 for hydrogen in your calculations, the sig figs should be based on 3.45g (3 sig figs) not 100.79 or 1.008.