Search found 19 matches
- Sun Mar 19, 2017 1:13 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3917280
Re: Post All Chemistry Jokes Here
Organic chemistry is difficult. Those who study it have alkynes of trouble.
- Thu Mar 16, 2017 10:47 pm
- Forum: *Cycloalkanes
- Topic: What is this structure?
- Replies: 2
- Views: 1556
Re: What is this structure?
I believe it should be 1-ethyl- 2-methyl-cyclopropane. If the numbering is the same, give the first substituent the lower number.
- Wed Mar 15, 2017 1:12 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Quiz 3 Winter 2017
- Replies: 183
- Views: 30089
Re: Quiz 3 Winter 2017
Julie Barreto 3A wrote:how would you draw out 2-butene or anything with a number in front of it ???
In that case, the 2 simply indicate the location of the double bond. So the double would be between the 2nd and 3rd carbon in your carbon chain drawing.
- Sat Mar 11, 2017 9:40 pm
- Forum: *Alkanes
- Topic: Naming [ENDORSED]
- Replies: 93
- Views: 17068
Re: Naming [ENDORSED]
I have a question about page 94 in the course reader from yesterday's lecture. We went over pentyl and isopentyl, but I thought you use neo instead of iso for pentane and beyond. Shouldn't the name be neopentyl instead of isopentyl? Neo is used for substituents that have the formula C(CH3)3 while i...
- Sat Mar 11, 2017 9:37 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam Details and Review Sessions Winter 2017
- Replies: 114
- Views: 27361
Re: Final Exam Details and Review Sessions Winter 2017
Will the final cover all material up to Friday's lecture?
- Tue Mar 07, 2017 6:46 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Quiz 3 Winter 2017
- Replies: 183
- Views: 30089
Re: Quiz 3 Winter 2017
how would you draw out 2-butene or anything with a number in front of it ??? Remember that 'ene ' just means that it has double bonds and the number indicates on which carbon the double bond is being located. What u can do first is to write out all carbons, place the double where needed and fill it...
- Sun Mar 05, 2017 5:00 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3917280
Re: Post All Chemistry Jokes Here
An optimist sees a glass half full with water.
A pessimist sees a glass half empty.
A chemist sees a glass full with water and air.
A pessimist sees a glass half empty.
A chemist sees a glass full with water and air.
- Tue Feb 21, 2017 11:44 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3917280
Re: Post All Chemistry Jokes Here
A proton and a neutron are walking down the street.
The proton says, "Wait, I dropped an electron help me look for it."
The neutron says "Are you sure?" The proton replies "I'm positive."
The proton says, "Wait, I dropped an electron help me look for it."
The neutron says "Are you sure?" The proton replies "I'm positive."
- Sun Feb 12, 2017 11:31 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3917280
Re: Post All Chemistry Jokes Here
Have you heard the one about a chemist who was reading a book about helium?
He just couldn't put it down.
He just couldn't put it down.
- Sun Jan 22, 2017 6:33 pm
- Forum: Calculating Work of Expansion
- Topic: Reversible and Isothermal
- Replies: 4
- Views: 849
Re: Reversible and Isothermal
I think isothermal system is a system that has a consistent heat source around it and it can affect work by either expansion or compression with the piston. If the gas expands (piston moves out), the system is doing work but heat around the area will replenish the lost energy as heat, therefore keep...
- Sun Oct 23, 2016 2:27 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: What are considered thhe e- in the outer shell?
- Replies: 3
- Views: 918
Re: What are considered thhe e- in the outer shell?
When forming ions, Cobalt would use the 4s electrons since those electrons are in the highest energy level and furthest away from the nucleus.
- Sun Oct 23, 2016 2:18 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configurations
- Replies: 2
- Views: 721
Re: Electron Configurations
I believe we have to write it in increasing numerical order because the d orbitals become lower in energy once the s orbitals have been filled. Let's take iron, Fe, for example. Once the 4s orbitals have been filled and the electrons start to occupy the 3d orbitals, the 3d orbitals become lower in e...
- Sun Oct 23, 2016 1:56 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Writing the Electron Configurations
- Replies: 1
- Views: 539
Re: Writing the Electron Configurations
Since the 3d orbitals is lower in energy than the 4s (after electrons have moved on to occupy the 3d shell), the electrons in copper would have to fill up the 3d so it would take one electron away from the 4s shell. Having a full 3d shell lowers the overall energy, providing more stability for the a...
- Wed Oct 19, 2016 1:20 am
- Forum: Ionic & Covalent Bonds
- Topic: Ch 3 #9,11 [ENDORSED]
- Replies: 5
- Views: 1077
Re: Ch 3 #9,11 [ENDORSED]
A metal with a +2 charge that has 25e- means the neutral atom would have a total of 25+2=27e- (which is the element Cobalt) because a positive charge means that electrons were lost when bonding.
- Fri Oct 14, 2016 11:39 pm
- Forum: Lewis Structures
- Topic: Lewis Structure Octet Rule [ENDORSED]
- Replies: 3
- Views: 2360
Re: Lewis Structure Octet Rule [ENDORSED]
I believe a double or triple bond is only needed when you have used up all the valence electrons in your Lewis structure and the central atom does not obey the octet rule (having a full shell of 8 electrons). For example, nitrate ion, NO3-, has a total of 5+3(6)+1=24 valence electrons but if you wer...
- Fri Oct 14, 2016 11:30 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionization Energy
- Replies: 7
- Views: 1578
Re: Ionization Energy
Yes, the second ionization energy will always be more than the first for every atom because it will take more energy to remove the second electron, since before it is positively charged, making it easier to remove the electron. When it becomes neutral, it's harder to remove the electron. Wait, did ...
- Mon Oct 03, 2016 2:39 am
- Forum: Properties of Light
- Topic: Question about n1 and n2
- Replies: 4
- Views: 4365
Re: Question about n1 and n2
Professor Lavelle said "n1 will be the final energy level the electron is at, where n2 will be the initial. Remember the electrons will move from a higher energy state to a lower energy state." Those 2 links might help you all understand them a little better. https://lavelle.chem.ucla.edu/...
- Mon Oct 03, 2016 2:19 am
- Forum: Properties of Light
- Topic: Increasing Intensity in Photoelectric Effect [ENDORSED]
- Replies: 9
- Views: 2303
Re: Increasing Intensity in Photoelectric Effect [ENDORSED]
So for further clarification, the intensity of the light has no effect until the energy of the photon reaches the work function? Also, I'm confused on what happens to the excess energy from the light. Yes, in the photoelectric effect, light acts as a particle so the intensity of the light only mean...
- Sat Oct 01, 2016 3:26 pm
- Forum: Properties of Light
- Topic: Question 1.11
- Replies: 2
- Views: 582
Re: Question 1.11
It doesn't matter where the energy level it starts from, the only thing you need to watch out for is where the energy level goes to, which will tell you to which series the lines belong to. For example, Balmer series lower energy level is 2 while Lyman series lower energy level is 1.