Search found 30 matches

by Adela Henry 1I
Tue Jun 05, 2018 8:20 pm
Forum: Lewis Structures
Topic: Test 3 Question 2
Replies: 5
Views: 213

Re: Test 3 Question 2

Oh, I see. Thank you guys for your help!
by Adela Henry 1I
Tue Jun 05, 2018 8:17 pm
Forum: Lewis Structures
Topic: Test 3 Question 2
Replies: 5
Views: 213

Re: Test 3 Question 2

This is what I did.
#2.jpg
by Adela Henry 1I
Tue Jun 05, 2018 8:07 pm
Forum: Lewis Structures
Topic: Test 3 Question 2
Replies: 5
Views: 213

Test 3 Question 2

Hi, for question 2 I had to find the most stable lewis structure for TiCl4. I thought I had did it right because of the formal charges but it was wrong. Could someone please explain the answer?
Thanks
by Adela Henry 1I
Thu May 31, 2018 8:04 pm
Forum: Dipole Moments
Topic: 4.25d - Lone Pairs
Replies: 2
Views: 188

Re: 4.25d - Lone Pairs

That is correct. When looking at dipole moments you need to consider the shape with regard to the effect lone pairs have on it. The lone pairs push atoms closer together and thus not all dipole moments will cancel out depending on the structure.
by Adela Henry 1I
Thu May 31, 2018 4:03 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: homework 4.29
Replies: 1
Views: 66

Re: homework 4.29

A smaller bond angle means that it has less of a chance of canceling each other out. When the bond angles are really small they go in practically the same direction meaning that the cancellation between the two is really small compared to larger bond angles where they could partially cancel each oth...
by Adela Henry 1I
Thu May 31, 2018 3:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.5 Confusion
Replies: 5
Views: 165

Re: 4.5 Confusion

When you draw out the lewis structure, there are 2 single bonds between the Cl and the O atoms. O-Cl-O. There is also a lone pair of electrons around the Cl atom. This makes 3 regions of electron density meaning that the shape is trigonal pyramidal based on the arrangement of electrons. When conside...
by Adela Henry 1I
Sat May 26, 2018 8:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shapes with different types of bonds
Replies: 3
Views: 122

Re: Shapes with different types of bonds

Bond angles will change because double and triple bonds have higher electron concentrations compared to single bonds which leads to electron repulsion, thus affecting the angles.
by Adela Henry 1I
Tue May 22, 2018 9:26 pm
Forum: Ionic & Covalent Bonds
Topic: Help on 3.11
Replies: 1
Views: 75

Re: Help on 3.11

For this question I started out by finding the element the given configuration led to. From there since it is a 3+ ion, that meant that 3 electrons were subtracted from the configuration so I added them back which meant first adding back the 2 in the s-orbital and then one in the d-orbital giving th...
by Adela Henry 1I
Tue May 22, 2018 9:20 am
Forum: Resonance Structures
Topic: 3.71
Replies: 1
Views: 160

Re: 3.71

That is correct. A structure with a lower formal charge is more likely to contribute to a resonance structure.
by Adela Henry 1I
Sat May 19, 2018 12:29 pm
Forum: Quantum Numbers and The H-Atom
Topic: Midterm Question
Replies: 13
Views: 449

Re: Midterm Question

This question from the midterm was number 2.27 from the homework.
by Adela Henry 1I
Thu May 17, 2018 12:01 pm
Forum: Significant Figures
Topic: how many place numbers to round to
Replies: 3
Views: 211

Re: how many place numbers to round to

Generally you would look at the information provided in the question. For the values given that you will use, whichever one has the lowest number of sig figs is the number of sig figs your answer should have.
by Adela Henry 1I
Wed May 16, 2018 9:38 pm
Forum: Ionic & Covalent Bonds
Topic: 3.23a & b
Replies: 2
Views: 98

Re: 3.23a & b

Basically the maximum positive and negative oxidation number is the maximum number of electrons the element has to gain or lose to reach the next noble gas. Positive = electrons lost. Negative = electrons gained.
by Adela Henry 1I
Fri May 11, 2018 2:40 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge: Lewis dot structures
Replies: 6
Views: 226

Re: Formal Charge: Lewis dot structures

Most likely yes because finding the formal charge helps to draw the most stable Lewis structure of the molecule.
by Adela Henry 1I
Wed May 09, 2018 8:22 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 2.45
Replies: 1
Views: 108

Re: 2.45

I don't fully know why that is but if it is any help, on the list of problems to do it said to omit part d from 45. We probably won't have a question like that on the midterm.
by Adela Henry 1I
Mon May 07, 2018 9:48 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: spd orbitals and electron config.
Replies: 3
Views: 158

Re: spd orbitals and electron config.

If the electron configuration is equal to a noble gas then you should use the one in the row above it and then write out the rest of the electron configuration. I think Dr. Lavelle would prefer this instead of just writing [Ar] because it shows that you understand how to write an electron configurat...
by Adela Henry 1I
Thu May 03, 2018 11:35 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configurations and Unpaired e- [ENDORSED]
Replies: 3
Views: 146

Re: Electron Configurations and Unpaired e- [ENDORSED]

There would be 2 unpaired electrons because the p-orbital can hold 6 electrons total. You would first begin by putting the 3 electrons as unpaired but then there is still 1 electron left which you would place with one of the first 3 single electrons. Thus there would be 1 pair and 2 unpaired electro...
by Adela Henry 1I
Wed May 02, 2018 8:57 pm
Forum: Trends in The Periodic Table
Topic: homework 2.59
Replies: 3
Views: 75

Re: homework 2.59

Atomic radii decrease across a period and since P3- appears first it has the greatest atomic radii and S2- and Cl- appear after it respectively on the periodic table meaning that their atomic radii are less than it. Therefore, since it asks for increasing atomic order it would be Cl- < S2- < P3- I d...
by Adela Henry 1I
Mon Apr 30, 2018 6:10 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: cation or anion?
Replies: 4
Views: 175

Re: cation or anion?

They should provide you with that information by giving you the element such as K+ or N^2- An element with a + is a cation (and thus you take away electrons) and an element with a - is an anion (so you add electrons). So two elements when in the ion form could have the same electron configuration bu...
by Adela Henry 1I
Sat Apr 28, 2018 7:49 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Electron Spin [ENDORSED]
Replies: 4
Views: 133

Re: Electron Spin [ENDORSED]

ms=+1/2 just means that the electron is spinning up whereas ms=-1/2 means that the electron is spinning down
by Adela Henry 1I
Fri Apr 27, 2018 4:20 pm
Forum: Photoelectric Effect
Topic: Test 2 #7 [ENDORSED]
Replies: 3
Views: 166

Test 2 #7 [ENDORSED]

Could someone explain how to do #7 from test 2
Thanks
by Adela Henry 1I
Mon Apr 23, 2018 11:34 am
Forum: DeBroglie Equation
Topic: DeBroglie
Replies: 5
Views: 276

Re: DeBroglie

DeBroglie's equation calculates the wavelength of any particle with wavelike properties and that have mass
lambda=Plack's constant(h)/(mass*velocity)
by Adela Henry 1I
Wed Apr 18, 2018 7:47 pm
Forum: Properties of Light
Topic: Homework 1.15
Replies: 3
Views: 158

Re: Homework 1.15

The formula is explained a little more in section 1.3 Atomic Spectra in the book.
R in the equation is Rydberg's constant and the n's are the lines (different quantum levels) on the spectrum you start at subtracted from the one you go to.
Hope this helps
by Adela Henry 1I
Mon Apr 16, 2018 8:32 am
Forum: Significant Figures
Topic: Zeros in Sig Figs
Replies: 3
Views: 251

Re: Zeros in Sig Figs

0.09 would have 1 sig fig because the zeros come before the 9.
0.0900 would have 3 sig figs because there are 2 trailing zeros after the 9. the two zeros before the 9 are not counted as sig figs.
by Adela Henry 1I
Mon Apr 16, 2018 8:30 am
Forum: Significant Figures
Topic: how many sig figs in number [ENDORSED]
Replies: 1
Views: 133

Re: how many sig figs in number [ENDORSED]

It depends on where they fall in relation to numbers that are 1 or greater.
if the number is 0.00031 there are only 2 sig figs
if the number is 300001 then there are 6 sig figs
as far as applying this with scientific notation 0.00031 becomes 3.1x10^-4 and still has 2 sig figs
Hope this helps!
by Adela Henry 1I
Sun Apr 15, 2018 9:14 am
Forum: Properties of Light
Topic: Equations [ENDORSED]
Replies: 8
Views: 191

Re: Equations [ENDORSED]

It usually depends on what information is given in the question that I use to determine what equation to use. Wavelength c=v x and E=hv for energy of light. Use both when it is the ejection of an electron.
by Adela Henry 1I
Sat Apr 14, 2018 6:14 pm
Forum: Empirical & Molecular Formulas
Topic: Compound Order
Replies: 5
Views: 205

Re: Compound Order

For our purposes right now I don't think the order matters, but later on in the course it might become something to pay attention to. I usually remember the order with CHNOPS for the elements that are used the most. Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfer.
Hope this helps!
by Adela Henry 1I
Sat Apr 14, 2018 2:14 pm
Forum: *Black Body Radiation
Topic: Importance of Black Bodies?
Replies: 2
Views: 205

Re: Importance of Black Bodies?

I'm pretty sure we don't actually have to know anything about them for this course. They were only mentioned to show that unlike atoms and molecules, there is something that can absorb or emit 'all' frequencies. It was just used as a comparison.
by Adela Henry 1I
Thu Apr 12, 2018 12:58 pm
Forum: Significant Figures
Topic: Sig fig simple question [ENDORSED]
Replies: 5
Views: 228

Re: Sig fig simple question [ENDORSED]

If you only want 1 sig fig then you would round up to 1.
You don't have to put a decimal after the 1 because it is one sig fig without it but you can put it if you want to.
Hope this helps
by Adela Henry 1I
Tue Apr 10, 2018 2:32 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: rounding [ENDORSED]
Replies: 10
Views: 342

Re: rounding [ENDORSED]

Rounding for answers depends on the individual problem and its significant figures in the question. If the question has only 1 sig fig than rounding to 3 is fine but it it has 2 sig figs than you should leave it as 2.8
by Adela Henry 1I
Mon Apr 09, 2018 5:32 pm
Forum: Properties of Light
Topic: Frequency vs Cycle
Replies: 5
Views: 277

Re: Frequency vs Cycle

Frequency and cycle are the same thing because 1 cycle per second is called a Hertz which is the unit used for frequency.

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