Search found 30 matches
Re: Oxidation
The oxidation number of a free element is always 0. The oxidation number of a monatomic ion equals the charge of the ion. The oxidation number of H is +1, but it is -1 in when combined with less electronegative elements. The oxidation number of O in compounds is usually -2, but it is -1 in peroxides...
- Sun Jun 10, 2018 7:44 pm
- Forum: Hybridization
- Topic: Electron densisty
- Replies: 5
- Views: 848
Re: Electron densisty
To find the electron density you would use the Lewis structure and count the areas of electron density around the central atom. You would do this by counting each double and triple bond as one area of high electron density and every lone pair as an area of high electron density.
- Sun Jun 10, 2018 7:38 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: polar/nonpolar
- Replies: 3
- Views: 498
Re: polar/nonpolar
The nonpolar molecules are those in which the forces cancel out and the polar molecules are molecules that have unequal dipole charges that don’t cancel out.
- Sun Jun 03, 2018 10:11 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Double bond
- Replies: 5
- Views: 765
Re: Double bond
The length of the bond is determined by the number of bonded electrons (the bond order). The higher the bond order, the stronger the pull between the two atoms and the shorter the bond length.
- Sun Jun 03, 2018 10:08 pm
- Forum: Hybridization
- Topic: Electron Promotion
- Replies: 2
- Views: 4491
Re: Electron Promotion
Can hybridization take place without electron promotion?
- Sun Jun 03, 2018 9:31 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone pairs
- Replies: 7
- Views: 821
Re: Lone pairs
The lone pair would cause the repulsion because of how close it is to the nucleus of the central atom.
- Sun May 27, 2018 11:03 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR confusion
- Replies: 8
- Views: 1320
Re: VSEPR confusion
VSEPR is how we predict the geometry of molecules from the number of electron pairs surrounding their central atoms. It helps us get a 3-D picture of what molecules actually look like.
- Sun May 27, 2018 10:11 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR
- Replies: 3
- Views: 385
Re: VSEPR
The type of bond doesn’t affect the formula so a double bond would still show up as AX.
- Sun May 27, 2018 9:38 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone pairs on non-central atoms
- Replies: 4
- Views: 806
Re: Lone pairs on non-central atoms
lone pairs on non-central atoms affect the bond angle
- Sun May 20, 2018 11:49 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Trends of Polarizing Power
- Replies: 4
- Views: 14002
Re: Trends of Polarizing Power
Yes cations and anions show opposite polarizability trends because cations are smaller than their parent atoms and less polarizable and anions show the opposite trend.
- Sun May 20, 2018 9:08 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Order of Increasing Polarization
- Replies: 2
- Views: 436
Re: Order of Increasing Polarization
The bigger atoms should have bigger polarizabililty, so the size has a direct relationship with polarizability.
- Sun May 20, 2018 8:49 pm
- Forum: Dipole Moments
- Topic: polarization power
- Replies: 3
- Views: 483
Re: polarization power
The ability of a cation to distort an anion is the polarization power and the tendency of the anion to become polarized by the cation is polarizability
- Sun May 20, 2018 8:43 pm
- Forum: Bond Lengths & Energies
- Topic: Test 3
- Replies: 8
- Views: 840
Re: Test 3
Yes we have to know what was covered in lecture last week that had to do with chapter 3.
- Sun May 13, 2018 10:38 pm
- Forum: Lewis Structures
- Topic: Meaning of chemical bond
- Replies: 5
- Views: 647
Re: Meaning of chemical bond
When we draw a line in a covalent bond means the electrons are being shared because the line is how we represent the sharing in a covalent bond.
- Sun May 13, 2018 10:31 pm
- Forum: Photoelectric Effect
- Topic: Kinetic Energy
- Replies: 2
- Views: 424
Re: Kinetic Energy
This isn’t true because even though it is possible for kinetic energy to increase as frequency increases, that’s not always the case depending on what the threshold energy, since kinetic energy only increases after surpassing the threshold energy.
- Sun May 13, 2018 10:21 pm
- Forum: Significant Figures
- Topic: diference in sig figs
- Replies: 5
- Views: 567
Re: diference in sig figs
Could you please give an example of how it would work for sig figs with addition/subtraction? Would that mean that adding something like 3.045+7.26 would result in an answer with only two figures after the decimal?
- Sun May 06, 2018 11:16 pm
- Forum: DeBroglie Equation
- Topic: De Brogiles wavelength
- Replies: 4
- Views: 746
Re: De Brogiles wavelength
You would use lambda= h/mv but would have to find the mass of the neon atom and plug that value into the equation.
- Sun May 06, 2018 10:52 pm
- Forum: *Black Body Radiation
- Topic: Midterm?
- Replies: 3
- Views: 858
Re: Midterm?
Dr. Lavelle had said that we aren't required to know this according to the 14A syllabus.
- Sun May 06, 2018 10:32 pm
- Forum: Properties of Light
- Topic: 4b practice midterm
- Replies: 11
- Views: 1632
Re: 4b practice midterm
How does work function fit into the problem? Is it only necessary in order to show us that this is a moving electron?
- Sun Apr 29, 2018 11:38 pm
- Forum: Photoelectric Effect
- Topic: increasing frequency/ light intensity
- Replies: 5
- Views: 1362
Re: increasing frequency/ light intensity
Since wavelength=speed of light/ frequency, changing the frequency affects the wavelength.
- Sun Apr 29, 2018 11:29 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Using shorthand [Ar] [ENDORSED]
- Replies: 5
- Views: 600
Re: Using shorthand [Ar] [ENDORSED]
I think the closest noble gas would probably be best for the shorthand.
- Tue Apr 24, 2018 7:36 pm
- Forum: Properties of Electrons
- Topic: electron mass
- Replies: 1
- Views: 286
electron mass
Will the mass of an electron be one of the values given to us on the exams?
- Sun Apr 22, 2018 11:09 pm
- Forum: DeBroglie Equation
- Topic: 1.39 and 1.23
- Replies: 3
- Views: 489
Re: 1.39 and 1.23
For the tests I think we will be given any information about conversions that most of us wouldn't know since we are being tested on concepts and applications, not conversions such as those from eV to J.
- Sun Apr 22, 2018 10:58 pm
- Forum: Einstein Equation
- Topic: When to use E=hc/wavelength
- Replies: 6
- Views: 2752
Re: When to use E=hc/wavelength
A lot of times we will use multiple equations to solve one problem so we might use what is given in one equation in order to plug that answer into the other equation.
- Sun Apr 15, 2018 11:52 pm
- Forum: Properties of Light
- Topic: Homework? [ENDORSED]
- Replies: 10
- Views: 1098
Re: Homework? [ENDORSED]
The homework should be on what you prefer to practice more from every section up until now which includes the quantum world and review of chemical and physical principles.
- Sun Apr 15, 2018 11:47 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing Chemical Equations and Combustion
- Replies: 7
- Views: 1027
Re: Balancing Chemical Equations and Combustion
When the reactants of combustion are given, the products will include H2O and CO2.
- Sun Apr 15, 2018 11:44 pm
- Forum: SI Units, Unit Conversions
- Topic: Moles mols mol? [ENDORSED]
- Replies: 21
- Views: 9358
Re: Moles mols mol? [ENDORSED]
All formats mean the same thing but we usually right it as mols in our answers.
- Wed Apr 11, 2018 11:13 am
- Forum: SI Units, Unit Conversions
- Topic: Length Units
- Replies: 15
- Views: 1539
Re: Length Units
Yes, when the units are not specified I think we would always answer the question in SI units.
- Fri Apr 06, 2018 12:05 pm
- Forum: Empirical & Molecular Formulas
- Topic: Homework Question
- Replies: 4
- Views: 743
Re: Homework Question
You would multiply by three in order to get to the closest full number and you would have to multiply the one by three too, giving you 8,8, and 3.
- Fri Apr 06, 2018 12:02 pm
- Forum: Balancing Chemical Reactions
- Topic: H.5.b [ENDORSED]
- Replies: 7
- Views: 919
Re: H.5.b [ENDORSED]
Yes you would just multiply the the N3 by 2 and the OH by 2 in order to be able to continue balancing the equation