Search found 31 matches

by Yitzchak Jacobson 1F
Mon Jun 11, 2018 1:03 am
Forum: Resonance Structures
Topic: How to tell when an molecule is resonant?
Replies: 7
Views: 269

Re: How to tell when an molecule is resonant?

you can tell when a molecule is resonant by knowing if there are multiple ways to draw the lewis structure.
Hope this helps you :)
by Yitzchak Jacobson 1F
Mon Jun 11, 2018 12:53 am
Forum: Bond Lengths & Energies
Topic: Bond length
Replies: 5
Views: 215

Re: Bond length

I believe you can tell which atom has a longer bond length by looking at how many electrons are present within the atoms.
I hope this answers your question :)
by Yitzchak Jacobson 1F
Mon Jun 11, 2018 12:48 am
Forum: Electronegativity
Topic: electronegativity chart
Replies: 11
Views: 607

Re: electronegativity chart

I don't believe its necessary to memorize it, but its best to know that it increases from left to right.
Hope this helps :)
by Yitzchak Jacobson 1F
Sun Jun 03, 2018 10:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Benzene structure
Replies: 2
Views: 90

Re: Benzene structure

Hello :)
I believe since we have gone over it, we will be expected to know how to draw it. I suggest going over it just in case it may appear on the final as well.
Really hope this answers your question! :)
by Yitzchak Jacobson 1F
Sun Jun 03, 2018 10:04 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Bond types
Replies: 6
Views: 137

Re: Bond types

Hello :)
I believe Professor Lavelle was trying to give us the overall 3-D model perspective by using dashed, and dotted lines. This gave us a clear understanding of how the model is portrayed.
I hope this helps :)
by Yitzchak Jacobson 1F
Sun Jun 03, 2018 9:53 pm
Forum: Hybridization
Topic: VSEPR
Replies: 11
Views: 428

Re: VSEPR

Hello :)
I believe VSEPR stands for valence shell electron pair repulsion. this is usually used to predict geometry molecules.
I hope this answers your question!
by Yitzchak Jacobson 1F
Sun Jun 03, 2018 9:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone pairs
Replies: 7
Views: 166

Re: Lone pairs

Hello :)
I believe the lone pair would cause the repulsion due to the distance it is from the central atom.
Really hope this helps!
by Yitzchak Jacobson 1F
Sun May 27, 2018 11:29 pm
Forum: Octet Exceptions
Topic: Octet Exception
Replies: 7
Views: 274

Re: Octet Exception

Hello, how are you?
To answer your question, to understand which elements have an incomplete octet, there is an option to memorize them. Another way is to memorize that period 3 on the periodic table have an octet exception rule.
by Yitzchak Jacobson 1F
Sun May 27, 2018 11:25 pm
Forum: Octet Exceptions
Topic: Octet Rules
Replies: 4
Views: 197

Re: Octet Rules

Hello :)
To answer your question, boron isn't the only element to have an incomplete octet. If you take a look at group 3 on the periodic table, those elements have incomplete octets as well.
by Yitzchak Jacobson 1F
Sun May 27, 2018 11:23 pm
Forum: Octet Exceptions
Topic: 3.61
Replies: 4
Views: 301

Re: 3.61

Hello, I believe since iodine is the least electronegative, it is centered in the middle. Also since it is an exception to the octet rule, you can add the excess lone pairs to it.
Really hope this helps :)
by Yitzchak Jacobson 1F
Sun May 20, 2018 11:17 pm
Forum: Electronegativity
Topic: Carbon and Sulfur electronegativity?
Replies: 4
Views: 1163

Re: Carbon and Sulfur electronegativity?

How I understand this concept of the periodic table is by always looking at fluorine and oxygen as the most electronegative. This could really help you decipher how the elements electronegativity's differ. I hopes this helps you! :)
by Yitzchak Jacobson 1F
Sun May 20, 2018 11:11 pm
Forum: Electronegativity
Topic: Isoelectronic [ENDORSED]
Replies: 11
Views: 506

Re: Isoelectronic [ENDORSED]

How I interpret atoms being isoelectronic, is the same as them both having the same chemical properties, and the same number of electrons. Really hope this is helpful :)
by Yitzchak Jacobson 1F
Sun May 20, 2018 11:06 pm
Forum: DeBroglie Equation
Topic: De Broglie Wavelength on the Midterm
Replies: 4
Views: 180

Re: De Broglie Wavelength on the Midterm

Hello, I believe I had a similar question regarding the midterm as well. I finally realized that if you see what the question is asking, we can tell that we must use the De Broglies wavelength Equation. Really hope this helps you :)
by Yitzchak Jacobson 1F
Sun May 13, 2018 11:16 pm
Forum: Empirical & Molecular Formulas
Topic: Molecular to Empirical
Replies: 9
Views: 341

Re: Molecular to Empirical

In this case, I would just leave it the same. I understand your confusion regarding this topic because I had a very similar problem.
Hope this info helps! :)
by Yitzchak Jacobson 1F
Sun May 13, 2018 11:14 pm
Forum: DeBroglie Equation
Topic: Bohr vs Speed of Light Equation
Replies: 3
Views: 138

Re: Bohr vs Speed of Light Equation

What really helps me solving problems and deciding between the bohr and the speed of light equation Is by examining what the question is asking, such as in terms of units. for example for solving for wavelength, you could use c=(lambda)(wavelength).
by Yitzchak Jacobson 1F
Sun May 13, 2018 11:09 pm
Forum: Properties of Light
Topic: Test 2 Question 4
Replies: 8
Views: 243

Re: Test 2 Question 4

Hello, At first I assumed that you would use the ryberg equation to solve the problem, but then I realized you can just solve it by using the equation
E=hc/lamda,
Really hopes this helps :)
by Yitzchak Jacobson 1F
Sun May 06, 2018 11:24 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Constant [ENDORSED]
Replies: 6
Views: 200

Re: Rydberg Constant [ENDORSED]

Hello:)
To answer your question, the Ryberg constant is R=3.28984 x 10^ 15 HZ.
You don't have to remember it though, because the formulas will be provided during the Midterm/Final Exam.
I hope this helps :)
by Yitzchak Jacobson 1F
Sun May 06, 2018 11:15 pm
Forum: Ionic & Covalent Bonds
Topic: Midterm Topics [ENDORSED]
Replies: 33
Views: 1676

Re: Midterm Topics [ENDORSED]

According to my understanding, only chapters 1 and 2 will be covered on the midterm. I remember him mentioning this in class, during his Friday lecture review.
by Yitzchak Jacobson 1F
Sun May 06, 2018 11:09 pm
Forum: Photoelectric Effect
Topic: Intensity of Photon
Replies: 8
Views: 282

Re: Intensity of Photon

I feel that what needs to be emphasized is the type of frequency. For example, by increasing the intensity of a photon with a long wavelength may emit little to know electrons. while on the other hand, increasing the intensity of a photon with a short wavelength will mostly like increase the amount ...
by Yitzchak Jacobson 1F
Mon Apr 30, 2018 4:47 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg [ENDORSED]
Replies: 4
Views: 162

Re: Rydberg [ENDORSED]

Ive had a similar problem regarding this equation also, and I realized that removing the negative sign in general allows more a more proficient answer. Hope this helps you :)
by Yitzchak Jacobson 1F
Mon Apr 30, 2018 4:44 pm
Forum: DeBroglie Equation
Topic: De Brogiles wavelength
Replies: 4
Views: 190

Re: De Brogiles wavelength

I think the problem here is the method of getting the mass of the element to solve for the wavelength. De Broglie's equation would definitely solve for this by using lamda=h/mv. really hope this helps :)
by Yitzchak Jacobson 1F
Mon Apr 30, 2018 4:37 pm
Forum: Properties of Light
Topic: Equations for light [ENDORSED]
Replies: 4
Views: 124

Re: Equations for light [ENDORSED]

Yes, those are very essential equations that are needed to prepare for the test/ midterm. But Keep in mind, it depends on what the question is asking and what the given values are in order to solve It. For example, you can solve velocity by using De Broglie's equation if you have the mass, and planc...
by Yitzchak Jacobson 1F
Sun Apr 22, 2018 11:56 pm
Forum: DeBroglie Equation
Topic: Wavelength= (h/p) [ENDORSED]
Replies: 7
Views: 299

Re: Wavelength= (h/p) [ENDORSED]

the reason why that formula doesn't apply to light is because it doesn't contain mass. hope this answers your question :)
by Yitzchak Jacobson 1F
Sun Apr 22, 2018 11:50 pm
Forum: SI Units, Unit Conversions
Topic: Avogadro #
Replies: 9
Views: 356

Re: Avogadro #

I believe that Avogadro's number can be very useful when trying to do conversions in chemistry calculations. An example that can be considered is attempting to convert a calculation to particles per mole.
by Yitzchak Jacobson 1F
Sun Apr 22, 2018 11:42 pm
Forum: Ideal Gases
Topic: Reading the textbook [ENDORSED]
Replies: 81
Views: 26759

Re: Reading the textbook [ENDORSED]

In my opinion I feel like the textbook can be very helpful when filling in gaps for chemistry topics to get more clarity. with that said, when I have difficulty understanding certain concepts that Professor Lavelle covers, I find it very useful to watch is lectures online first, and then reading the...
by Yitzchak Jacobson 1F
Mon Apr 16, 2018 12:09 am
Forum: Empirical & Molecular Formulas
Topic: Molecular to Empirical
Replies: 9
Views: 341

Re: Molecular to Empirical

in this case that you specifically mentioned, I advise leaving both the empirical and molecular formulas the same.
by Yitzchak Jacobson 1F
Mon Apr 16, 2018 12:07 am
Forum: Significant Figures
Topic: Significant Figures When Multiplying and Dividing [ENDORSED]
Replies: 4
Views: 177

Re: Significant Figures When Multiplying and Dividing [ENDORSED]

Hello, there is no distinct rule for counting significant figures for both multiplication, or division. they both follow the same general pattern of sig figs.
by Yitzchak Jacobson 1F
Mon Apr 16, 2018 12:05 am
Forum: Properties of Light
Topic: Wavelength [ENDORSED]
Replies: 9
Views: 260

Re: Wavelength [ENDORSED]

according my studies, wavelength does not need to be at peaks, but I do believe it has to be at a very specific point.
by Yitzchak Jacobson 1F
Sun Apr 08, 2018 11:10 pm
Forum: Limiting Reactant Calculations
Topic: Reactant vs. Reagent [ENDORSED]
Replies: 23
Views: 6349

Re: Reactant vs. Reagent [ENDORSED]

I believe reagents are substances added to a system for a chemical reaction, while a reactants are a substance consumed in a chemical reaction.
by Yitzchak Jacobson 1F
Sun Apr 08, 2018 11:05 pm
Forum: Significant Figures
Topic: Why are sig figs important?
Replies: 13
Views: 665

Re: Why are sig figs important?

I believe significant figures are extremely important, and they will seem very essential as you continue to use them. The reason why sig figs are so important is because it allows your calculations to be more accurate which leads to a better answer overall. I honestly feel like they are pretty essen...
by Yitzchak Jacobson 1F
Sun Apr 08, 2018 10:55 pm
Forum: General Science Questions
Topic: Rusty on High School Chem [ENDORSED]
Replies: 113
Views: 35863

Re: Rusty on High School Chem [ENDORSED]

I believe Professor Lavelle offers many recourses to refresh the memories for high school chemistry. What I believe will be truly helpful is attending his timed office hours, and even attending a step up session to get detailed, fluent instructions on how to solve the difficult problems you are deal...

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