Search found 36 matches

by Jack Hewitt 4G
Mon Feb 11, 2019 9:28 pm
Forum: Administrative Questions and Class Announcements
Topic: Lyndon's HOTDOG MIDTERM REVIEW SESSION!! FINALLY!
Replies: 47
Views: 1662

Re: Lyndon's HOTDOG MIDTERM REVIEW SESSION!! FINALLY!

I will not be able to make the review session tonight. Can someone post the answers given?
by Jack Hewitt 4G
Thu Dec 06, 2018 6:34 pm
Forum: Einstein Equation
Topic: Numbers to memorize
Replies: 22
Views: 262

Re: Numbers to memorize

Soyoung Park 1H wrote:Do we have to memorize numbers such as c=3.00x10^8 m/s and planck's constant (h=6.63x10^-34Js) for the test?

No you do not we are given a constants and equations sheet. However it may be helpful to memorize them to some extent so you can do problems faster.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:33 pm
Forum: Einstein Equation
Topic: de brogile equation
Replies: 4
Views: 180

Re: de brogile equation

danielruiz1G wrote:in the de Broglie equation why does it state that any moving "particle" , when the examples talk about cars. can any moving object talk have a wavelength?

Yes any moving object has wavelength, but with large objects such as cars the wavelength is irrelevant.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:31 pm
Forum: Einstein Equation
Topic: E=hv
Replies: 14
Views: 214

Re: E=hv

Chase Yonamine 1K wrote:In the equation, E=hv, does E represent the energy of the photon or does it represent the energy required to remove an electron?

e represents the energy of a photon. The works function represents the energy required to remove an electron.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:30 pm
Forum: Photoelectric Effect
Topic: Kinetic energy
Replies: 8
Views: 92

Re: Kinetic energy

Madeline Lequang 1G wrote:Does the formula (1/2)mv^2 only apply to kinetic energy? or can it be used for other types of energy?

It only applies to kinetic energy.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:29 pm
Forum: Properties of Light
Topic: Speed of light
Replies: 13
Views: 86

Re: Speed of light

When doing calculations, should we use 2.99792 × 10 8 m.s -1 or 3.00 × 10 8 m.s -1 for the speed of light? I used the 3.00 × 10 8 m.s -1 on the midterm and got an answer that was two hundredths off and got it marked wrong, so what should be the accurate number to use? Look at the sig figs in the pr...
by Jack Hewitt 4G
Thu Dec 06, 2018 6:27 pm
Forum: Trends in The Periodic Table
Topic: Higher Electron Affinity Nitrogen or Carbon
Replies: 4
Views: 65

Re: Higher Electron Affinity Nitrogen or Carbon

Sarah Bui 4I wrote:Hi! I was just wondering which element has a higher electron affinity nitrogen or carbon and why? I think this is one of the exceptions and I am not sure.

Carbon has a greater affinity for electrons than nitrogen because of its half filled p subshell which makes it more stable than Nitrogen.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:25 pm
Forum: Balancing Chemical Reactions
Topic: Why do we balance chemical equations?
Replies: 8
Views: 105

Re: Why do we balance chemical equations?

Madelyn Cearlock wrote:For the question that asks why do we balance chemical equations, what was the exact answer that was desired? Thank you!

Because of the law of conservation of mass.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:25 pm
Forum: Balancing Chemical Reactions
Topic: Combustion Equation
Replies: 8
Views: 265

Re: Combustion Equation

chrisavalos- 1K wrote:What is the rule for a combustion equation? Do they always produce Carbon Dioxide and Water? I have just never been sure of this. Thank You.

Yes, combustion reactions will always produce CO2 and H2O.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:24 pm
Forum: Significant Figures
Topic: When to round the answers to significant figures
Replies: 11
Views: 204

Re: When to round the answers to significant figures

Do we round the answer in every step of the calculation, or do we just round the final answer to the number of significant figures? Because when I round the answer in every step, my final answers are often different from those given by the textbook. It is best to only round your answers at the very...
by Jack Hewitt 4G
Thu Dec 06, 2018 6:23 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molar Mass
Replies: 8
Views: 243

Re: Molar Mass

Lily Smith 4C wrote:Where do you find the mass of an atom on the periodic table?

It is listed under the element in their box on the periodic table.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:21 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 8
Views: 97

Re: Formal Charge

Number of valence electrons - (number of lone electrons + number of lines drawn)
by Jack Hewitt 4G
Thu Dec 06, 2018 6:19 pm
Forum: Electronegativity
Topic: Electronegativity
Replies: 4
Views: 43

Re: Electronegativity

chrisdinkel_1K wrote:do we have to determine relative Electronegativites by periodic trends or is it given?

You have to use periodic trends to determine relative electronegativities.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:16 pm
Forum: Lewis Structures
Topic: Elements that break the octet rule
Replies: 6
Views: 52

Re: Elements that break the octet rule

So I know that Br, I, and P can break the octet rule in lewis structures, but I read that there are other elements that can do this too, like Cl occasionally. Which elements are we required to know that break the octet rule for this class? It is better to think of it conceptually that if an element...
by Jack Hewitt 4G
Thu Dec 06, 2018 6:14 pm
Forum: Trends in The Periodic Table
Topic: Bond Lenghts
Replies: 6
Views: 92

Re: Bond Lenghts

How can you tell which molecules have a greater bond length without having its Lewis structure? I know when you have two ions you look for polarizability but what about when you have multiple elements involved? You would need to draw the Lewis structure to determine which molecules have a greater b...
by Jack Hewitt 4G
Thu Dec 06, 2018 6:12 pm
Forum: Properties of Electrons
Topic: Electron Configuration
Replies: 7
Views: 59

Re: Electron Configuration

melissa_dis4F wrote:For the electron configuration of Pd I get [Kr]4d^8 5s^2 but it is [Kr] 4d^10. My question is do we change it to [Kr] 4d^10 because we should fill in the entire d orbital before continuing to the 5s orbital? Is this always?

Yes this is always. It is one of the exceptions to the octet rule.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:11 pm
Forum: Photoelectric Effect
Topic: Work Function
Replies: 14
Views: 198

Re: Work Function

Melissa Villanueva 3D wrote:How would we solve for the work function? Like what type of information would be given to use in order to find the work function and how would we use the given. Thanks!

You rearrange the formula as you would with an algebraic equation and plug in what is given to solve for the work function.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:08 pm
Forum: Electronegativity
Topic: Trend of Electronegativity
Replies: 9
Views: 80

Re: Trend of Electronegativity

chrisavalos- 1K wrote:I was wondering what the trend for electronegativity was, is it the same as ionization energy?

Yes, the trend for electronegativity is the same as the trend for ionization energy.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:07 pm
Forum: Octet Exceptions
Topic: Exceptions
Replies: 7
Views: 90

Re: Exceptions

jane_ni_3b wrote:How should we know which ones are exceptions?

The most common exceptions we deal with are found in the 3rd period because of an unfilled d-orbital.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:05 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: AXE formula
Replies: 18
Views: 441

Re: AXE formula

Arlene Linares 3A wrote:How do we figure out the AXE formula? I am still having trouble with this.

A is the central atom. X is the number of atoms bonded to the central atom. E is the number of lone pairs on the central atom.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:03 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: AXE formula
Replies: 18
Views: 441

Re: AXE formula

danielruiz1G wrote:is it possible to determine the shape of a molecule if you're only given the AXE formula, if so how do you do it?

Yes because the AXE formula tells you the regions of electron density which is all you need to determine the shape.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:02 pm
Forum: Hybridization
Topic: hybridization
Replies: 13
Views: 89

Re: hybridization

KarlaArevalo4D wrote:Does anyone have an easy way to find the hybridization of the central atom they are able to share? Much appreciated.

The easiest way is to consider the number of regions with electron density. This includes lone pairs.
by Jack Hewitt 4G
Thu Dec 06, 2018 6:00 pm
Forum: Hybridization
Topic: pi vs sigma
Replies: 12
Views: 74

Re: pi vs sigma

Arshia Ramesh 1G wrote:i read on one of the reviews that a pi bond is weaker than a sigma bond but why is that?

It is because a pi bond does not allow for rotation and would break while a sigma bond does allow for rotation.
by Jack Hewitt 4G
Thu Dec 06, 2018 5:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Square Planar
Replies: 12
Views: 83

Re: Square Planar

Phoebe Chen 4I wrote:Are the bond angles in square planar less than or equal to 90?

They are equal to 90.
by Jack Hewitt 4G
Thu Dec 06, 2018 5:57 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: AX3E
Replies: 18
Views: 85

Re: AX3E

kevinav wrote:What would be the molecular shape for the general formula AX3E

The molecule would have a trigonal pyramidal molecular shape.
by Jack Hewitt 4G
Thu Dec 06, 2018 5:55 pm
Forum: Hybridization
Topic: lone pairs
Replies: 20
Views: 92

Re: lone pairs

Moryel Yashar 1J wrote:Are lone pairs taken into consideration when determining the hybridization of a central atom?

Yes lone pairs are taken into consideration because they are still areas of electron density.
by Jack Hewitt 4G
Thu Dec 06, 2018 5:54 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Determining Lewis Acids and Bases
Replies: 1
Views: 20

Determining Lewis Acids and Bases

How do I determine which compound is a Lewis Acid and which compound is a Lewis base?
by Jack Hewitt 4G
Fri Nov 02, 2018 6:33 pm
Forum: Lewis Structures
Topic: How to decide central atom?
Replies: 6
Views: 65

Re: How to decide central atom?

Nicholas Le 3A wrote:Is the central atom in the Lewis structures based off of which atom has the lowest electronegativity or which atom has the lowest ionization energy?


It is based off of lowest ionization energy.
by Jack Hewitt 4G
Fri Nov 02, 2018 6:31 pm
Forum: Administrative Questions and Class Announcements
Topic: Scantron
Replies: 6
Views: 56

Re: Scantron

904837647 wrote:So the midterm should be formatted just like the test?


Yes, the midterm should be formatted similarly to the tests.
by Jack Hewitt 4G
Fri Nov 02, 2018 6:29 pm
Forum: Student Social/Study Group
Topic: Midterm
Replies: 15
Views: 249

Re: Midterm

Do we know how many questions from each section will be in the test? Like how many from the fundamentals, quantum, and chemical bonds? I know there’s 8 but how is it going to be divided? My TA said that the amount of questions from each section would correlate to the amount of time we spent on said...
by Jack Hewitt 4G
Fri Oct 26, 2018 1:13 pm
Forum: Properties of Light
Topic: Electromagnetic Spectrum
Replies: 5
Views: 94

Re: Electromagnetic Spectrum

You do not need to fully memorize the spectrum but it will definitely be helpful to be familiar with it for the course.
by Jack Hewitt 4G
Fri Oct 26, 2018 1:10 pm
Forum: DeBroglie Equation
Topic: Measurable wavelength properties
Replies: 5
Views: 125

Re: Measurable wavelength properties

The car was too large to have "measurable wavelike properties".
by Jack Hewitt 4G
Fri Oct 26, 2018 1:07 pm
Forum: Einstein Equation
Topic: Units
Replies: 6
Views: 133

Re: Units

The test required students to know correct units as well as significant figures.
by Jack Hewitt 4G
Fri Oct 05, 2018 8:23 pm
Forum: SI Units, Unit Conversions
Topic: How does grading for discussion posts work?
Replies: 73
Views: 1293

Re: How does grading for discussion posts work?

Does anyone actually know when the discussion posts are due?
by Jack Hewitt 4G
Fri Oct 05, 2018 8:22 pm
Forum: Balancing Chemical Reactions
Topic: States of Matter
Replies: 11
Views: 131

Re: States of Matter

Does anyone know if we need to write the different states of matter in each equation?
by Jack Hewitt 4G
Fri Oct 05, 2018 8:21 pm
Forum: Administrative Questions and Class Announcements
Topic: Number of questions on test one [ENDORSED]
Replies: 39
Views: 16670

Re: Number of questions on test one [ENDORSED]

Dr. Lavelle hasn't said how many questions the test will be nor how it will be graded.

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