Search found 38 matches

by Eli Esagoff_1I
Fri Jun 08, 2018 5:56 pm
Forum: Photoelectric Effect
Topic: Visible or measurable light
Replies: 4
Views: 120

Re: Visible or measurable light

I don't think we have to know this specifically. But we did learn that visible light has a wavelength of 400-700nm.
by Eli Esagoff_1I
Fri Jun 08, 2018 5:55 pm
Forum: Sigma & Pi Bonds
Topic: exceptions
Replies: 2
Views: 190

Re: exceptions

I don't think so. From what we learned in class, a double bond is always one pi bond and one sigma bond.
by Eli Esagoff_1I
Fri Jun 08, 2018 5:54 pm
Forum: Identifying Acidic & Basic Salts
Topic: salt in water
Replies: 2
Views: 160

Re: salt in water

He was explaining that both Na+ and Cl- in table salt does not change the pH of water. This does not apply to all types of salts.
by Eli Esagoff_1I
Wed Jun 06, 2018 11:35 pm
Forum: Naming
Topic: Naming on Final
Replies: 8
Views: 360

Re: Naming on Final

I would try to avoid the naming problems on the homework.
by Eli Esagoff_1I
Wed Jun 06, 2018 11:33 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Tetrahedral and Square planar
Replies: 8
Views: 421

Re: Tetrahedral and Square planar

Tetrahedral is when the central atom is surrounded by four bonding atoms. Square planar is when the central atom is surrounded by four bonded atoms and two lone pairs.
by Eli Esagoff_1I
Wed Jun 06, 2018 11:30 pm
Forum: Lewis Structures
Topic: Lowest energy lewis structure
Replies: 5
Views: 1334

Re: Lowest energy lewis structure

You want all formal charge to be 0 or closest to 0 when there is a charge on the molecule.
by Eli Esagoff_1I
Sat Jun 02, 2018 11:04 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Bond types
Replies: 6
Views: 180

Re: Bond types

They are all the same types of bonds. The different ways that there are drawn are just for the three dimensional structure.
by Eli Esagoff_1I
Sat Jun 02, 2018 11:02 am
Forum: Lewis Structures
Topic: d-block Lewis structures
Replies: 3
Views: 192

Re: d-block Lewis structures

I don't think its any different than a normal lewis structure.
by Eli Esagoff_1I
Sat Jun 02, 2018 11:01 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Naming shape
Replies: 7
Views: 253

Re: Naming shape

I believe the ones with lone pairs have different names for the shapes.
by Eli Esagoff_1I
Sat May 26, 2018 12:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polarity
Replies: 1
Views: 93

Re: Polarity

Could be that anions attract electrons form the cations.
by Eli Esagoff_1I
Sat May 26, 2018 12:28 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shapes with different types of bonds
Replies: 3
Views: 137

Shapes with different types of bonds

I know that the shapes are still the same when you have single, double or triple bonds, but do the bond angles change when the types of bonds are different?
by Eli Esagoff_1I
Sat May 26, 2018 12:25 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Remembering Bond Angles
Replies: 4
Views: 186

Re: Remembering Bond Angles

Yes, I think you should know the bond angles associated with each shape.
by Eli Esagoff_1I
Tue May 22, 2018 9:20 pm
Forum: Dipole Moments
Topic: Topics on Test 3
Replies: 2
Views: 102

Topics on Test 3

Are dispersion forces, induced dipole-induced dipole, London forces on test 3?
by Eli Esagoff_1I
Wed May 16, 2018 10:42 am
Forum: Formal Charge and Oxidation Numbers
Topic: Reducing formal charge number
Replies: 3
Views: 160

Re: Reducing formal charge number

To reduce formal charges it is effective to move lone pairs and bonds around while continuously checking the formal charge, so it can be closest to 0. You should definitely look at formal charges in every problem that you do.
by Eli Esagoff_1I
Wed May 16, 2018 10:38 am
Forum: Determining Molecular Shape (VSEPR)
Topic: How to determine molecular shape
Replies: 5
Views: 192

Re: How to determine molecular shape

I don't think we learned this in lecture yet but I think its based on the number of bonds and what type of bonds there are.
by Eli Esagoff_1I
Wed May 16, 2018 10:37 am
Forum: Ionic & Covalent Bonds
Topic: Naming Molecules
Replies: 5
Views: 121

Naming Molecules

Do we need to know how to name molecules or determine molecules based on their names for exam 3 or the final?
by Eli Esagoff_1I
Sat May 12, 2018 1:45 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Calculating formal charges
Replies: 5
Views: 196

Re: Calculating formal charges

The formal charge for each element is:

FC = VE (valence electrons) - LPE (lone pair electrons) - 0.5BE (half the bonding electrons).

Hope this helped.
by Eli Esagoff_1I
Sat May 12, 2018 1:43 pm
Forum: Ionic & Covalent Bonds
Topic: "1.20A or 1.40A"
Replies: 2
Views: 86

Re: "1.20A or 1.40A"

I don't think we have to know how to calculate bonds lengths in this course.
by Eli Esagoff_1I
Sat May 12, 2018 1:41 pm
Forum: Ionic & Covalent Bonds
Topic: Metals
Replies: 4
Views: 125

Re: Metals

They lost electrons because it is a lot easier to lose 1-2 electrons that to gain 6-7 electrons.
by Eli Esagoff_1I
Sat May 12, 2018 1:39 pm
Forum: Octet Exceptions
Topic: Octet fule in forming compounds
Replies: 2
Views: 133

Re: Octet fule in forming compounds

If calcium loses two electrons (becoming Ca^2a) it will have the structure of Argon, having eight valence electrons.
by Eli Esagoff_1I
Sat May 12, 2018 1:37 pm
Forum: Ionic & Covalent Bonds
Topic: Lewis Structure vs Resonance Structure
Replies: 6
Views: 166

Re: Lewis Structure vs Resonance Structure

Resonance structures are just different lewis structures. Lewis structures are the individual structures within the resonance structures. They are not two different things, they are integrated together.
by Eli Esagoff_1I
Wed May 09, 2018 12:02 am
Forum: Trends in The Periodic Table
Topic: Electron Affinity Exceptions
Replies: 3
Views: 220

Electron Affinity Exceptions

Do we need to know the exceptions to the trend of electron affinity for the upcoming exam?
by Eli Esagoff_1I
Sun May 06, 2018 4:22 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Shapes of orbitals
Replies: 6
Views: 276

Re: Shapes of orbitals

I don't think so. I hope not.
by Eli Esagoff_1I
Sun May 06, 2018 4:21 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 4s and 3d
Replies: 4
Views: 152

Re: 4s and 3d

I think that it is due to the difference in n. n=4 is a higher energy level than n=3.
by Eli Esagoff_1I
Sun May 06, 2018 4:16 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity
Replies: 3
Views: 157

Electron Affinity

I am having trouble understanding how energy is released or spent when you add an electron to an element. Can someone please explain this to me? I understand the trend of electron affinity and how it increases towards the right (where the elements want to become stable).
by Eli Esagoff_1I
Sun Apr 29, 2018 1:45 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: What does electron spin actually mean? [ENDORSED]
Replies: 9
Views: 378

Re: What does electron spin actually mean? [ENDORSED]

Not sure, but I think for this class we just have to know that for two electrons to bond they have to spin in opposite directions.
by Eli Esagoff_1I
Sun Apr 29, 2018 1:42 pm
Forum: Photoelectric Effect
Topic: Test 2 #7 [ENDORSED]
Replies: 3
Views: 174

Re: Test 2 #7 [ENDORSED]

For this question you had to use the equation: (Energy photon - threshold energy = kinetic energy). The kinetic energy is 0 so you just do (hc)/wavelength = the given threshold energy. After plugging in variable, you can sold for wavelength which equals 2.20x10^-7 m. Hope this helped.
by Eli Esagoff_1I
Sun Apr 29, 2018 1:39 pm
Forum: Photoelectric Effect
Topic: What is work function? [ENDORSED]
Replies: 15
Views: 1592

Re: What is work function? [ENDORSED]

Work function is just a synonym for threshold energy. It is not an equation, it is the minimum energy needed for an electron to be ejected from a metal. The value is usually given.
by Eli Esagoff_1I
Sat Apr 21, 2018 4:55 pm
Forum: Properties of Light
Topic: test 2
Replies: 18
Views: 592

Re: test 2

I think the questions will be similar to the examples we did in class and the questions we get for homework.
by Eli Esagoff_1I
Sat Apr 21, 2018 4:54 pm
Forum: General Science Questions
Topic: Test #2 [ENDORSED]
Replies: 6
Views: 446

Re: Test #2 [ENDORSED]

I would recommend doing as many practice as possible including using the calculator so you do not have trouble with time.
by Eli Esagoff_1I
Sat Apr 21, 2018 4:52 pm
Forum: DeBroglie Equation
Topic: DeBrogile Module
Replies: 6
Views: 200

Re: DeBrogile Module

It should definitely be converted. I would recommend checking your conversion factors (you should multiply by 1,000 and divide by 3,600)!
by Eli Esagoff_1I
Sun Apr 15, 2018 12:03 am
Forum: Properties of Light
Topic: Equations [ENDORSED]
Replies: 8
Views: 196

Re: Equations [ENDORSED]

I used them based on what information is given. You should almost always be given 2/3!
by Eli Esagoff_1I
Sun Apr 15, 2018 12:01 am
Forum: Balancing Chemical Reactions
Topic: Balancing Chemical Equations and Combustion
Replies: 7
Views: 337

Re: Balancing Chemical Equations and Combustion

The products of combustion are always CO2 and H2O.
by Eli Esagoff_1I
Sun Apr 15, 2018 12:00 am
Forum: Balancing Chemical Reactions
Topic: How to Balance [ENDORSED]
Replies: 5
Views: 181

Re: How to Balance [ENDORSED]

I like to start with the easiest coefficients and then go on from there.
by Eli Esagoff_1I
Sat Apr 14, 2018 11:58 pm
Forum: Empirical & Molecular Formulas
Topic: Combustion Reaction [ENDORSED]
Replies: 6
Views: 249

Re: Combustion Reaction [ENDORSED]

The combusted element produces CO2 + H2O after reacting with oxygen.
by Eli Esagoff_1I
Sat Apr 14, 2018 11:55 pm
Forum: Photoelectric Effect
Topic: Dividing by Avogadro's constant [ENDORSED]
Replies: 2
Views: 78

Re: Dividing by Avogadro's constant [ENDORSED]

The question gave a value that was for 1 mole of an element and he asked how we can find out the value for an individual molecule. To find this you divide by Avogadro's constant because there are 6.022 x 10^23 molecular units in a mole.
by Eli Esagoff_1I
Sat Apr 14, 2018 11:52 pm
Forum: Significant Figures
Topic: Expected mastery of Significant Figures
Replies: 6
Views: 289

Re: Expected mastery of Significant Figures

I think you should figure it out how to use sig figs as soon as possible just in case!
by Eli Esagoff_1I
Sat Apr 14, 2018 11:46 pm
Forum: SI Units, Unit Conversions
Topic: Do we have to convert final answer to make it simpler? [ENDORSED]
Replies: 4
Views: 216

Re: Do we have to convert final answer to make it simpler? [ENDORSED]

I'm pretty sure either way is fine. The question might specify by asking "how many meters" and then you would put: x 10^-9.

Go to advanced search