Search found 32 matches

by Hussein Saleh 1L
Tue Jun 05, 2018 12:52 pm
Forum: Naming
Topic: Coordination Compound confusion [ENDORSED]
Replies: 4
Views: 287

Coordination Compound confusion [ENDORSED]

What aspect of coordination compounds will be on the final. I’m pretty confused on whether to study it or not.
by Hussein Saleh 1L
Mon Jun 04, 2018 4:46 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR shape and bond angles
Replies: 5
Views: 196

Re: VSEPR shape and bond angles

Mariah Guerrero 1J wrote:Do we have to know the specific bond angles for certain molecular shapes. For example, would it be acceptable to say (on a test) that sulfite ion, SO3 2-, have bond angles less than 109.5? Are approximations ok to state?

Yes according to my PLF that is fine.
by Hussein Saleh 1L
Thu May 31, 2018 3:27 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Helpful Chart
Replies: 18
Views: 516

Re: Helpful Chart

Rebekah Kaufman 1L wrote:Is there a way to calculate the bond angles or is it just a memorization thing?


Unfortunately, Its the one thing we MUST memorize for the course. It should not be too hard though with practice we should be fine while also strengthing our lewis structure skills!
by Hussein Saleh 1L
Thu May 31, 2018 3:18 pm
Forum: Hybridization
Topic: sp^3 orbitals
Replies: 3
Views: 127

Re: sp^3 orbitals

I don't think you necessarily need to memorize it but understand the overall concept just like we've been doing for the last 9 weeks. The only thing I see worthy of memorizing is the shape names and the bond lengths.
by Hussein Saleh 1L
Thu May 31, 2018 3:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR AXE
Replies: 4
Views: 155

Re: VSEPR AXE

When using the VSEPR formula, knowing that for E you write the number of electron pairs, what would you write when dealing with a radical? Do you put E 0.5 or is it still E 1? Thanks in advance! In nature there would probably never be a formula with just one electron and anyways E asks for the numb...
by Hussein Saleh 1L
Thu May 31, 2018 2:54 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.5 Confusion
Replies: 5
Views: 178

4.5 Confusion

Hello,

I am having trouble with the answer to this question, "What's the shape of ClO2+" The answer says its trigonal planar but shouldn't it be bent?

Thanks
by Hussein Saleh 1L
Thu May 31, 2018 2:52 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR shape and bond angles
Replies: 5
Views: 196

Re: VSEPR shape and bond angles

Hi, I read that molecules with the same VSEPR formula have the same shape, but differ in bond angle. How would I determine the difference between the bond angles in different molecules with the same shape and VSEPR formula? Also how would I be able to recognize the exceptions to this? In the book i...
by Hussein Saleh 1L
Tue May 22, 2018 2:59 pm
Forum: Bond Lengths & Energies
Topic: Test 3 Material Question
Replies: 3
Views: 240

Re: Test 3 Material Question

Bijal Luhar wrote:Is Test 3 covering everything in this section (Chemical Bonds) of chemistry community? Does anyone know the list of specific topics we must must completely understand?


Check the outline! But you should know bond length, covalent vs. ionic bonds, drawing lewis structure, radicals, etc.
by Hussein Saleh 1L
Tue May 22, 2018 2:58 pm
Forum: Lewis Structures
Topic: OH Bonds
Replies: 2
Views: 92

Re: OH Bonds

If we are given O and H along with any other element in an chemical formula do we automatically pair O and H together? Is this always true, or are there exceptions? Can someone explain why? If you are given (OH-) in a problem which includes the parenthesizes then it will be group together on the le...
by Hussein Saleh 1L
Mon May 21, 2018 1:35 pm
Forum: Lewis Structures
Topic: 3.63 [ENDORSED]
Replies: 2
Views: 101

Re: 3.63 [ENDORSED]

I doubt it matters at the moment. I think it's doing that to mimic the 3D structue (maybe I dont know how its 3D structure looks like) but on the test you shouldn't worry about where you put your CL's around it as long as it follows the correct structure and most importantly is right
by Hussein Saleh 1L
Mon May 21, 2018 1:33 pm
Forum: Lewis Structures
Topic: Lewis Structure ClONO3 [ENDORSED]
Replies: 2
Views: 157

Re: Lewis Structure ClONO3 [ENDORSED]

Lone Pairs often make molecules a bit more unstable so if you get the opportunity to replace it with an actual bond go for it!
by Hussein Saleh 1L
Mon May 21, 2018 1:28 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Low Energy
Replies: 2
Views: 180

Re: Low Energy

Regardless energy is being produced by the overall lewis structure. So their is high energy produced.
by Hussein Saleh 1L
Wed May 16, 2018 1:25 pm
Forum: Ionic & Covalent Bonds
Topic: Naming Molecules
Replies: 5
Views: 121

Re: Naming Molecules

I doubt we'd need to learn all the names but I'd say to get familiar with them cause really it's quite simple with practice
by Hussein Saleh 1L
Wed May 16, 2018 1:15 pm
Forum: Ionic & Covalent Bonds
Topic: Percentage Ionic Character
Replies: 4
Views: 183

Re: Percentage Ionic Character

What is the minimum percentage requirement for a bond to be labeled as ionic? Does it just have to have more than 50 percent ionic character? Remember in lecture on Friday, Professor Lavelle stated that any difference in electronegativity that is greater than 2 should be labeled as an ionic bond an...
by Hussein Saleh 1L
Wed May 16, 2018 1:06 pm
Forum: Ionic & Covalent Bonds
Topic: Percentage Ionic Character
Replies: 4
Views: 183

Re: Percentage Ionic Character

Sarah Brecher 1I wrote:Will we be given the electronegativity of the elements so that we can determine if it is an ionic / covalent bond?

I think we would have to determine that if given a periodic table. Its pretty easy to do so ionization energy increases from left to right and from down to up.
by Hussein Saleh 1L
Wed May 16, 2018 1:02 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: How to determine molecular shape
Replies: 5
Views: 188

Re: How to determine molecular shape

We haven't really mentioned that yet. We are just learning the basics at the moment
by Hussein Saleh 1L
Wed May 16, 2018 1:01 pm
Forum: Ionic & Covalent Bonds
Topic: Bonds between 1.5 and 2 [ENDORSED]
Replies: 5
Views: 181

Bonds between 1.5 and 2 [ENDORSED]

In class professor Lavelle talked about the difference between ionic and covalent bonds in terms of differences between electronegativity. My question is what type of bonds are found in between the difference of electronegativities of 1.5 and 2.
by Hussein Saleh 1L
Thu May 03, 2018 9:41 pm
Forum: Quantum Numbers and The H-Atom
Topic: Bohr radius [ENDORSED]
Replies: 3
Views: 170

Re: Bohr radius [ENDORSED]

Outline #2 does not mention that we need to necessarily know those and I don't remember hearing it in Lecture but I could be wrong. I wouldn't worry about it.
by Hussein Saleh 1L
Thu May 03, 2018 9:31 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Homework question 2.1
Replies: 2
Views: 65

Re: Homework question 2.1

If you look on Page 178 on our textbook you can see a chart that describes what each symbol means. N represents the shell of the atom (which is basically size). L is the subshell of the atom which represents the overall shape. I hope this helped!
by Hussein Saleh 1L
Thu May 03, 2018 6:10 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Question 1.19 Help
Replies: 2
Views: 90

Question 1.19 Help

Hello, I'm having trouble understanding how to go about these two parts of question 2.19: (b) How many values of ml are allowed for an electron in a 6d-subshell? (c) How many values of ml are allowed for an electron in a 3p-subshell? The answer key says the answers are (b):5 and (c):3. Anyone care t...
by Hussein Saleh 1L
Mon Apr 23, 2018 8:40 pm
Forum: Administrative Questions and Class Announcements
Topic: Test Time
Replies: 6
Views: 292

Re: Test Time

Test 1 is known as the time-crunched test because there's so much going on according to previous 14A students (who had Dr. Lavelle of course). We shouldn't have to deal with the time that bad anymore to my understanding.
by Hussein Saleh 1L
Mon Apr 23, 2018 8:38 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect
Replies: 2
Views: 114

Re: Photoelectric Effect

Binding energy refers to the energy that bounds the electron to the metal, while the threshold energy refers to the minimum energy necessary to eject an electron from the metal surface. If you ever forget the difference between the two on an exam the answer is in the names. Binding energy = bounded...
by Hussein Saleh 1L
Mon Apr 23, 2018 8:34 pm
Forum: Significant Figures
Topic: Expected mastery of Significant Figures
Replies: 6
Views: 289

Re: Expected mastery of Significant Figures

Thanks everyone. I asked around and heard that we were expected to figure it out by test 2 but no official word has been given
by Hussein Saleh 1L
Mon Apr 23, 2018 8:32 pm
Forum: Properties of Light
Topic: Homework Problem(s) [ENDORSED]
Replies: 6
Views: 214

Re: Homework Problem(s) [ENDORSED]

I believe the masses would be given on the tests. You can even see the sheet given on Test 1 which was passed back last week
by Hussein Saleh 1L
Mon Apr 23, 2018 8:30 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Homework Questions for Week IV
Replies: 3
Views: 114

Re: Homework Questions for Week IV

Homework can be chosen from any chapter as long as we went over it. Just a reminder not to turn in a problem you may have already turned in. I'd suggest doing problems from Dr. Lavelle's email.
by Hussein Saleh 1L
Mon Apr 23, 2018 8:24 pm
Forum: Properties of Light
Topic: Test 2 Material
Replies: 12
Views: 416

Re: Test 2 Material

Madeleine Farrington 1B wrote:Will accurate use of significant figures be graded on test 2?

I've heard that we will be graded on Sig Figs this exams.
by Hussein Saleh 1L
Sat Apr 14, 2018 4:15 pm
Forum: Balancing Chemical Reactions
Topic: Another Way to Balance
Replies: 7
Views: 266

Re: Another Way to Balance

Sadly Guess and Check is your best bet when it comes to solving those problems. It may not be quick at times but it gets the job done
by Hussein Saleh 1L
Sat Apr 14, 2018 4:03 pm
Forum: Significant Figures
Topic: Expected mastery of Significant Figures
Replies: 6
Views: 289

Expected mastery of Significant Figures

By what test are we expected to know how to determine how many sig figs to use in a problem?
by Hussein Saleh 1L
Sat Apr 14, 2018 4:01 pm
Forum: Photoelectric Effect
Topic: E(Photon) greater than/equal to (Energy Remove e-) [ENDORSED]
Replies: 2
Views: 87

Re: E(Photon) greater than/equal to (Energy Remove e-) [ENDORSED]

The statement from the book is correct. I think you may have accidentally wrote it down backwards. If E(photon) < threshold energy then the electron will not eject. If E(photon) > threshold energy then the electron will eject. Yeah, I agree with the book. I even have it written down in my notes tha...
by Hussein Saleh 1L
Sat Apr 14, 2018 3:57 pm
Forum: Properties of Electrons
Topic: History of experiments on the model of atom
Replies: 7
Views: 334

Re: History of experiments on the model of atom

I doubt we would ever have this question a test/midterm/final. Especially cause it was never mentioned in lecture.
by Hussein Saleh 1L
Sat Apr 14, 2018 3:50 pm
Forum: Properties of Light
Topic: Units for Wavelengths [ENDORSED]
Replies: 4
Views: 119

Re: Units for Wavelengths [ENDORSED]

Usually you'd give the answer in the desired unit. For example, some problems might say, "Give in pg". However in the rare case that the question does not tell you which unit to use, you usually want to give the same unit given in the question itself. For example, if the question states, &...
by Hussein Saleh 1L
Sat Apr 14, 2018 3:37 pm
Forum: *Black Body Radiation
Topic: Importance of Black Bodies?
Replies: 3
Views: 360

Re: Importance of Black Bodies?

Hi!
During lecture on Friday, Professor Lavelle said that we won't be going too in-depth in regards to black bodies so I wouldn't worry about it.

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