Search found 51 matches
- Sat Dec 12, 2020 6:24 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2996792
Re: Post All Chemistry Jokes Here
Helium makes my laugh sound like he he he
- Sat Dec 12, 2020 6:21 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: chelating ligands [ENDORSED]
- Replies: 51
- Views: 96687
Re: chelating ligands [ENDORSED]
Does this mean polydentate ligands and chelating ligands are the same thing?
- Sat Dec 12, 2020 5:39 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Saying Thank You to Dr. Lavelle
- Replies: 490
- Views: 513445
Re: Saying Thank You to Dr. Lavelle
Thank you Dr. Lavelle. I really enjoyed this class!
- Sat Dec 12, 2020 5:38 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Course Evaluations
- Replies: 9
- Views: 866
Re: Course Evaluations
I just clicked on the link that I got through an email. It worked fine for me. Maybe this can help?
- Sat Dec 12, 2020 5:37 pm
- Forum: Student Social/Study Group
- Topic: Final Jitters
- Replies: 457
- Views: 334046
Re: Final Jitters
As Dr. Lavelle said in his final review, don't use your energy to stress. We can use that time and energy to review another concept perhaps. Get some rest and make sure you are on a consistent sleeping pattern.
- Sat Dec 05, 2020 9:27 am
- Forum: General Science Questions
- Topic: Tricks for Knowing Locations of Metals and Nonmetals on Periodic Table
- Replies: 8
- Views: 5415
Re: Tricks for Knowing Locations of Metals and Nonmetals on Periodic Table
It is certainly good to memorize using the methods listed above, but I also recommend that you take into consideration each molecule your come across. I got into a habit of noting which elements seem present in certain situations, and this helps me understand or assume that certain elements are meta...
- Sat Dec 05, 2020 9:25 am
- Forum: General Science Questions
- Topic: Enrolling in Chem 14B and BL simultaneously?
- Replies: 14
- Views: 1602
Re: Enrolling in Chem 14B and BL simultaneously?
I would recommend taking them at separate times. A current junior at UCLA told me that most people just take the 14 series over the course of three quarters.
- Sat Dec 05, 2020 9:24 am
- Forum: General Science Questions
- Topic: study methods/recs
- Replies: 37
- Views: 2052
Re: study methods/recs
For me, I usually make sure that I fully understand all the lectures so that I have a strong foundation. Then, a week or two before whatever exam we have, I usually would go through textbook problems and work out every single one listed and review sapling.
- Sat Dec 05, 2020 9:22 am
- Forum: General Science Questions
- Topic: Grade Breakdown
- Replies: 35
- Views: 2124
Re: Grade Breakdown
Does anyone know the minimum points we can lose to maintain an A or A-? Or is he curving the grades later? I've mostly heard that he uses a straight grading scale with no curves (490/500=A+, 465/500=A and so on) but I'm not entirely sure on this. The only thing I know for sure is that he doesn't do...
- Sat Dec 05, 2020 9:21 am
- Forum: General Science Questions
- Topic: midterm 2 answers
- Replies: 30
- Views: 1997
Re: midterm 2 answers
You have to contact your TA to set up a separate time. Even then, you will not be able to visually see what you got wrong if I am not mistaken.
- Thu Nov 26, 2020 11:01 am
- Forum: General Science Questions
- Topic: Grades
- Replies: 30
- Views: 1948
Re: Grades
You can just click on CCLE, go to the chem page, and scroll down to the bottom left where it says grades to get an overview of your midterm grades and more.
- Thu Nov 26, 2020 11:00 am
- Forum: General Science Questions
- Topic: Grade Breakdown
- Replies: 35
- Views: 2124
Re: Grade Breakdown
Does anyone know the minimum points we can lose to maintain an A or A-? Or is he curving the grades later?
- Thu Nov 26, 2020 10:46 am
- Forum: General Science Questions
- Topic: # of chem posts
- Replies: 27
- Views: 1606
Re: # of chem posts
By now, you can check your grades on CCLE if you have 35 points to make sure that you have been on track.
- Thu Nov 26, 2020 10:45 am
- Forum: General Science Questions
- Topic: Finals
- Replies: 39
- Views: 2097
Re: Finals
Does anyone know if we get partial credits for questions on the finals?
- Thu Nov 26, 2020 10:44 am
- Forum: General Science Questions
- Topic: Grading Scale Chem 14A
- Replies: 11
- Views: 1083
Re: Grading Scale Chem 14A
I thought we didn't have a curve since people in groupme said like we can only miss a total of 17 points to maintain an A in the quarter.
- Sat Nov 21, 2020 12:57 pm
- Forum: General Science Questions
- Topic: Midterm Grades
- Replies: 30
- Views: 1293
Re: Midterm Grades
If I remember correctly, it took about a week on the first midterm, so hopefully ASAP.
- Sat Nov 21, 2020 12:51 pm
- Forum: General Science Questions
- Topic: bond lengths
- Replies: 10
- Views: 925
Re: bond lengths
There are a lot of factors aside from the number of bonds that determine bond length, so it is hard to say or apply that for every case.
- Sat Nov 21, 2020 12:47 pm
- Forum: General Science Questions
- Topic: Questions
- Replies: 2
- Views: 245
Re: Questions
A little late, but there are 16.
- Sat Nov 21, 2020 12:46 pm
- Forum: General Science Questions
- Topic: Which would have lower ionization energy?
- Replies: 13
- Views: 703
Re: Which would have lower ionization energy?
Cl would be. You can either look at the trends on the table, or just from the fact that N, O, F are one of the most electronegative elements, you can probably assume O has the higher electronegativity.
- Sat Nov 21, 2020 12:45 pm
- Forum: General Science Questions
- Topic: Midterm 2
- Replies: 8
- Views: 559
Re: Midterm 2
A little late, but it was the same haha I am sorry I could not be helpful before.
- Thu Nov 12, 2020 6:57 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Lowering Formal Charges
- Replies: 7
- Views: 371
Re: Lowering Formal Charges
I understand that having a formal charge of 0 is the best for any molecule, but would this be attainable by every molecule? How do you know if a formal charge for a molecule is the lowest it can get? Adding on to this, is having the central atom with a formal charge ideal if there is an overall cha...
- Thu Nov 12, 2020 6:54 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Sapling week 5/6 #5
- Replies: 6
- Views: 419
Re: Sapling week 5/6 #5
Carbon should have a charge of -2 because the equation says 4 - (4/2 + 4), which equals -2.
- Thu Nov 12, 2020 6:53 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Oxidization Numbers
- Replies: 10
- Views: 528
Re: Oxidization Numbers
If you are unsure or questioning something, you should probably learn it just to be safe. Better to know more than less. Good luck!
- Thu Nov 12, 2020 6:52 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Sapling #9
- Replies: 5
- Views: 353
Re: Sapling #9
Megan wrote a very clear explanation of why the oxidation number for Cl is +7, which was because oxygen is -2. However, there are exceptions to oxygen's oxidation number and I just wanted to point that out!
- Thu Nov 12, 2020 6:50 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Ionic Structures
- Replies: 6
- Views: 293
Re: Ionic Structures
You should aim for three main things:
1. make sure to have as many 0's as possible
2. aim for low magnitudes with non-zeros
3. have negative charges on most electronegative atoms
1. make sure to have as many 0's as possible
2. aim for low magnitudes with non-zeros
3. have negative charges on most electronegative atoms
- Sat Nov 07, 2020 9:46 am
- Forum: Ionic & Covalent Bonds
- Topic: Electron Affinity vs. Electronegativity
- Replies: 12
- Views: 1311
Re: Electron Affinity vs. Electronegativity
In short, electron affinity is the energy released as electrons are added to a neutral atom, whereas electronegativity is the ability to attract electrons. Therefore, these two are different.
- Sat Nov 07, 2020 9:44 am
- Forum: Ionic & Covalent Bonds
- Topic: Polarity
- Replies: 9
- Views: 451
Re: Polarity
If you are referring to ionic characters as in the partial positive and negative charges due to differences in electronegativities, then that probably means that the two are interchangeable in some ways.
- Sat Nov 07, 2020 9:42 am
- Forum: Ionic & Covalent Bonds
- Topic: Atomic Radius
- Replies: 38
- Views: 2955
Re: Atomic Radius
The more pairs of electrons and protons you have, the more attraction there is. Therefore, as you move right, these pairs increase and the radius gets smaller.
- Sat Nov 07, 2020 9:41 am
- Forum: Ionic & Covalent Bonds
- Topic: Coulomb's PE
- Replies: 3
- Views: 131
Re: Coulomb's PE
If you are concerned, might as well learn it just to be safe. Although the last midterm did have calculation problems, concept questions definitely took up a good part of the exam, so it may be a good idea to own it in your own words.
- Sat Nov 07, 2020 9:39 am
- Forum: Ionic & Covalent Bonds
- Topic: Electronegativity
- Replies: 16
- Views: 950
Re: Electronegativity
A lot of people answered the reason, but I just want to make a side note that knowing the electronegativity trend might be really helpful. It just makes our lives easier. While you are at it, might as well check out the trend for atomic radius as well.
- Sat Oct 31, 2020 1:35 pm
- Forum: General Science Questions
- Topic: Enrolling in Chem 14B and BL simultaneously?
- Replies: 14
- Views: 1602
Re: Enrolling in Chem 14B and BL simultaneously?
I would recommend taking them at separate times. Since you are already in 14A, might as well just do 14B next quarter and save the other for another time. However, if you think you can take them simultaneously, go for it! After all, you know yourself best.
- Sat Oct 31, 2020 1:34 pm
- Forum: General Science Questions
- Topic: Midterm Grades
- Replies: 30
- Views: 1293
Re: Midterm Grades
They will post it once everyone is done? is what I am guessing. I hope it went well for you.
- Sat Oct 31, 2020 1:33 pm
- Forum: General Science Questions
- Topic: Understanding Velocity
- Replies: 3
- Views: 172
Re: Understanding Velocity
You can use wavelength = h/mv, where m is mass of an electron and v is velocity.
- Sat Oct 31, 2020 1:32 pm
- Forum: General Science Questions
- Topic: Sapling Homework
- Replies: 14
- Views: 788
Re: Sapling Homework
You should just aim to do the first 19 questions as Dr. Lavelle told us in the emails. Hopefully the exam was not too bad for you!
- Sat Oct 31, 2020 1:30 pm
- Forum: General Science Questions
- Topic: polyatomic ions
- Replies: 6
- Views: 358
Re: polyatomic ions
We do not have to memorize them. Still would be good to be able to recognize them.
- Sun Oct 25, 2020 12:44 pm
- Forum: Photoelectric Effect
- Topic: Sapling HW Weeks 2, 3, 4 Question #9
- Replies: 10
- Views: 909
Re: Sapling HW Weeks 2, 3, 4 Question #9
You can use the E=hc/lambda equation to find the maximum wavelength. Since E is given in joules and you know h and c, just plug in the numbers to find wavelength in m. Then you convert that to angstrom via the conversion 1 A =1 x 10^-10m
- Sun Oct 25, 2020 12:38 pm
- Forum: Photoelectric Effect
- Topic: Wavelength in Photoelectric Effect
- Replies: 7
- Views: 318
Re: Wavelength in Photoelectric Effect
The wavelength depends mainly on which metal surface you are talking about. This means that you cannot take the same approach for every problem. It varies each time.
- Sun Oct 25, 2020 12:24 pm
- Forum: Photoelectric Effect
- Topic: Sapling HW 2 Question 4
- Replies: 6
- Views: 408
Re: Sapling HW 2 Question 4
It seems like you have the numbers that you can plug in to get the work function. Once you find that, divide the total energy by the work function to get the answer.
- Sun Oct 25, 2020 11:58 am
- Forum: Photoelectric Effect
- Topic: Photoelectric Effect Post-Module Assessment #29
- Replies: 4
- Views: 248
Re: Photoelectric Effect Post-Module Assessment #29
You can just divide the work function by the Avogadro's number for energy needed for just one sodium atom. You should also change the units to J, not kJ.
- Sun Oct 25, 2020 11:51 am
- Forum: Photoelectric Effect
- Topic: Calculations
- Replies: 18
- Views: 590
Re: Calculations
You should probably plug in the true values into your calculator. Keep in mind, however, the sig figs at the start. This way, you can simply round at the end.
- Sun Oct 18, 2020 12:40 am
- Forum: General Science Questions
- Topic: Balancing equations
- Replies: 19
- Views: 2488
Re: Balancing equations
There definitely are several ways you can go about in balancing equations. I'd say stick to what you have been doing. There is probably a mental map that you visualize before solving the problem, and it is probably the most efficient method for you.
- Sun Oct 18, 2020 12:39 am
- Forum: General Science Questions
- Topic: Polyatomic Ions
- Replies: 6
- Views: 354
Re: Polyatomic Ions
It would be a good idea to know the fundamentals. Even though the formulas are given, it is important that we utilize them and apply them to certain concepts. Nonetheless, it does not hurt to know them.
- Sun Oct 18, 2020 12:36 am
- Forum: General Science Questions
- Topic: Sapling Homework
- Replies: 14
- Views: 788
Re: Sapling Homework
It is probably a good idea to complete the sapling homework before your midterms. However, it may be better to focus on sticking with your own study tips so that you can own the information before your midterms. This can mean testing yourself on the content or creating study sets to review. Good luck!
- Sun Oct 18, 2020 12:31 am
- Forum: General Science Questions
- Topic: Kelvin
- Replies: 8
- Views: 408
Re: Kelvin
Kelvin does not use degrees. You can just leave it as __ Kelvin.
- Sun Oct 18, 2020 12:27 am
- Forum: General Science Questions
- Topic: Writing Formulas
- Replies: 10
- Views: 375
Re: Writing Formulas
For things like sulfuric acid, I believe that it is memorization. However, things like disulfur dichloride, there are a set of rules to know in order to figure out the formula. I hope this helps.
- Sun Oct 11, 2020 10:39 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Can I reply to a reply?
- Replies: 3
- Views: 144
Re: Can I reply to a reply?
You can simply click and the quotation button on the person's post that you want to reply to.
- Sun Oct 11, 2020 10:37 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Posting on Chemistry Community
- Replies: 7
- Views: 211
Re: Posting on Chemistry Community
We need to reply 5 times a week, which adds up to 50 points at the end of the quarter for a total of 50 points.
- Sun Oct 11, 2020 10:26 pm
- Forum: Significant Figures
- Topic: Sapling Question 2
- Replies: 14
- Views: 388
Re: Sapling Question 2
It would be positive two because when writing something into scientific notation, you are essentially undoing what you did in order to reach the correct scientific notation. You can always use the calculator to verify your answer, but you can also use this as a rule of thumb: if you go from a bigger...
- Sun Oct 11, 2020 10:23 pm
- Forum: Significant Figures
- Topic: What is the purpose of significant figures?
- Replies: 17
- Views: 1089
Re: What is the purpose of significant figures?
Significant figures are confusing and have several rules that one must adhere to. While the main purpose is to maintain order and to be as precise as possible. On the differences of adding/subtracting and multiplying/dividing, these are just rules that we must accept. Although it is good to always q...
- Sun Oct 11, 2020 10:17 pm
- Forum: Significant Figures
- Topic: Sapling HW #4
- Replies: 31
- Views: 1782
Re: Sapling HW #4
Trailing zeros with no decimal point are not significant numbers. That's why 950000 only has two significant figures. However, if there was a decimal, you would include the zeros because they are now significant. In the case of 80060, there are four significant numbers, which are "8006". T...
- Mon Oct 05, 2020 7:42 am
- Forum: Administrative Questions and Class Announcements
- Topic: Students in different time zones [ENDORSED]
- Replies: 27
- Views: 2244