Search found 30 matches

by Nienjou Claire 1E
Mon Jun 04, 2018 7:11 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: polar and nonpolar molecules
Replies: 5
Views: 173

Re: polar and nonpolar molecules

would you just have to know which bonds/molecules would produce a charge or is there a way to tell by looking at the structure?
by Nienjou Claire 1E
Mon Jun 04, 2018 6:36 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands
Replies: 3
Views: 122

Re: Ligands

A ligand is basically the atom that binds to the central atom in a coordinate compound.
by Nienjou Claire 1E
Mon Jun 04, 2018 6:34 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: pi and sigma bonds
Replies: 3
Views: 154

Re: pi and sigma bonds

I'm not quite sure of what you are asking for, but I'll write down my notes from what Professor Lavelle said in class. The bonds basically hold the atoms in a coordinate compound together. Sigma bonds: 2 orbitals, each with 1 electron; interact end-to-end to form 1 sigma-bond; allow bound atoms to r...
by Nienjou Claire 1E
Fri Jun 01, 2018 11:03 pm
Forum: Lewis Structures
Topic: d-block Lewis structures
Replies: 3
Views: 193

d-block Lewis structures

Can someone explain how to draw a Lewis structure of an element from the d-block?
by Nienjou Claire 1E
Fri Jun 01, 2018 11:01 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7606
Views: 1018060

Re: Post All Chemistry Jokes Here

I have many chemistry jokes, but I'm afraid they won't get a good reaction.
by Nienjou Claire 1E
Fri Jun 01, 2018 10:53 pm
Forum: Naming
Topic: Coordination compound
Replies: 6
Views: 298

Re: Coordination compound

A coordination compound basically consists of a central atom with ligands attached to it by covalent bonds
by Nienjou Claire 1E
Wed May 23, 2018 10:18 am
Forum: Formal Charge and Oxidation Numbers
Topic: Prioritizing Formal Charge
Replies: 2
Views: 180

Re: Prioritizing Formal Charge

I'm not sure if this is correct, but I remember that it is best if the center atom has a formal charge of zero but generally, the idea is to get all elements to be as close to 0 as possible.
by Nienjou Claire 1E
Wed May 23, 2018 10:16 am
Forum: Octet Exceptions
Topic: Maximum number of electrons in expanded octet
Replies: 1
Views: 147

Re: Maximum number of electrons in expanded octet

The most electrons you can add to an expanded octet is 10 because ultimately, you're filling up the d orbital and that can only hold up to 10.
by Nienjou Claire 1E
Wed May 23, 2018 10:15 am
Forum: Bond Lengths & Energies
Topic: bond length and charge
Replies: 3
Views: 286

bond length and charge

How does charge influence bond length? Does bond length increase as charge increases as well?
by Nienjou Claire 1E
Fri May 18, 2018 1:11 pm
Forum: Lewis Structures
Topic: Test #3
Replies: 11
Views: 380

Re: Test #3

Also, I remember Chem_Mod's answer in another topic, saying that Test 3 will not cover electron configuration since we were already tested about that on the midterm.
by Nienjou Claire 1E
Fri May 18, 2018 1:07 pm
Forum: Lewis Structures
Topic: Exceptions to the Octet
Replies: 5
Views: 169

Re: Exceptions to the Octet

I remember my TA saying that you can add up to 10 extra electrons since it is the d block that is involved in the expanded octet and it can hold ten electrons.
by Nienjou Claire 1E
Fri May 18, 2018 1:03 pm
Forum: Lewis Structures
Topic: 3.41c
Replies: 2
Views: 114

3.41c

For more complicated compounds such as the H2C(NH2)COOH given in part c of 3.41, how would you go about figuring out specifically which elements are bound to which ones and in which order? It seems like a rather arduous process to test out possible combinations until you get one that gives the right...
by Nienjou Claire 1E
Sun May 13, 2018 11:11 pm
Forum: Lewis Structures
Topic: resonance
Replies: 6
Views: 209

Re: resonance

Thanks so much: the replies really cleared it up! A follow-up question: if the correct lewis structure is a combination of the possible "correct" ones, why would we still need to calculate formal charge? Is that just to determine the result of resonance?
by Nienjou Claire 1E
Sun May 13, 2018 10:58 pm
Forum: Lewis Structures
Topic: resonance
Replies: 6
Views: 209

resonance

Can someone explain the concept of resonance? I still don't really understand what it is exactly and how it relates to drawing Lewis structures.
by Nienjou Claire 1E
Sun May 13, 2018 10:56 pm
Forum: Lewis Structures
Topic: Expanded Octet
Replies: 2
Views: 115

Re: Expanded Octet

Regarding the expanded octet, it's just that elements that are below the 3rd row have a d orbital or more that can bond if needed
by Nienjou Claire 1E
Sun May 06, 2018 9:19 pm
Forum: Empirical & Molecular Formulas
Topic: Test 1/ Question 8 [ENDORSED]
Replies: 6
Views: 384

Re: Test 1/ Question 8 [ENDORSED]

For this, you wouldn't need the mass of the molecule. The structures themselves give you the molecular formula since it shows you exactly how many of each element is in the molecule. You can literally count the how many of each element there are and that is basically the molecular formula. To get th...
by Nienjou Claire 1E
Sun May 06, 2018 9:15 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent vs. Ionic
Replies: 3
Views: 146

Re: Covalent vs. Ionic

First off, covalent bonds are between nonmetals and ionic bonds are between a metal and nonmetal. The biggest, and most important, difference is that elements in an ionic bond are more aggressive so it kind of takes the electron, which produces a charge for the overall molecule. Covalent bond elemen...
by Nienjou Claire 1E
Sun May 06, 2018 6:35 pm
Forum: Ionic & Covalent Bonds
Topic: Midterm Topics [ENDORSED]
Replies: 33
Views: 1913

Re: Midterm Topics [ENDORSED]

Also, does anyone know where we can get practice midterms? Does the test bank have any?
by Nienjou Claire 1E
Mon Apr 30, 2018 3:57 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Using the uncertainty principle [ENDORSED]
Replies: 2
Views: 161

Re: Using the uncertainty principle [ENDORSED]

Then, you would plug in 6.626 x 10^-34 for the h in h/2pi
by Nienjou Claire 1E
Mon Apr 30, 2018 3:50 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: cation or anion?
Replies: 4
Views: 182

cation or anion?

How do you know if an element will be a cation or anion if it is the same distance away from 2 different noble gases? Will they provide you with the information?
by Nienjou Claire 1E
Mon Apr 30, 2018 3:44 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 3d and 4s orbitals
Replies: 3
Views: 149

3d and 4s orbitals

Can someone explain in simple terms why 4s orbitals are a lower energy than 3d and thus should be written first?
by Nienjou Claire 1E
Sun Apr 22, 2018 6:24 pm
Forum: Photoelectric Effect
Topic: Threshold Energy [ENDORSED]
Replies: 4
Views: 138

Re: Threshold Energy [ENDORSED]

Work function and threshold energy are the same thing.
by Nienjou Claire 1E
Sun Apr 22, 2018 6:17 pm
Forum: Properties of Light
Topic: Wavelengths
Replies: 8
Views: 250

Re: Wavelengths

My TA said that just as you know the general ranges and order of the wavelengths you should be fine. She did say that it would be best if you knew that visible light is 400 to 700 nm.
by Nienjou Claire 1E
Sun Apr 22, 2018 6:11 pm
Forum: Administrative Questions and Class Announcements
Topic: Test Number 1
Replies: 10
Views: 460

Re: Test Number 1

The average for my section was around a 22/40. My friend told me that her TA said that they would try to make it so that most people at least passed but I don't know how exactly that's gonna happen. They did say that they were aware of how hard it was and that for test number 2, they would include a...
by Nienjou Claire 1E
Sun Apr 15, 2018 9:11 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7606
Views: 1018060

Re: Post All Chemistry Jokes Here

I don't trust atoms...
I heard they make up everything.
by Nienjou Claire 1E
Sun Apr 15, 2018 9:08 pm
Forum: SI Units, Unit Conversions
Topic: Units for Answer
Replies: 10
Views: 471

Re: Units for Answer

You could also see what units the original problem gives for the numbers and follow that.
by Nienjou Claire 1E
Sun Apr 15, 2018 9:04 pm
Forum: Ideal Gases
Topic: Reading the textbook [ENDORSED]
Replies: 128
Views: 75164

Re: Reading the textbook [ENDORSED]

I think reading the textbook definitely helps. Personally, I feel like it gives me a better overview of the big topics I am supposed to be learning. Professor Lavelle's lecture tend to be a little more focused on one specific topic and one specific example so I read the textbook to link ideas togeth...
by Nienjou Claire 1E
Sun Apr 08, 2018 9:42 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7606
Views: 1018060

Re: Post All Chemistry Jokes Here

Q: what kind of dogs do scientists have?
A: laboratory retrievers
by Nienjou Claire 1E
Sun Apr 08, 2018 9:39 pm
Forum: Ionic & Covalent Bonds
Topic: Types of Bonds
Replies: 10
Views: 377

Re: Types of Bonds

Yes, you are exactly right! The only difference is that an ionic bond is a bond between a metal and a nonmetal and then a metallic bond is between 2 metals. Again, just look at the periodic table to determine whether an element is a nonmetal or metal.
by Nienjou Claire 1E
Sun Apr 08, 2018 9:35 pm
Forum: Ionic & Covalent Bonds
Topic: Types of Bonds
Replies: 10
Views: 377

Re: Types of Bonds

To put it simply, a covalent bond is a bond between 2 nonmetals. You can just look up the elements on the periodic table to determine if it is a nonmetal. They are to the right of the "staircase"-like divider.

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