## Search found 32 matches

Sun Jun 10, 2018 6:04 pm
Forum: Lewis Structures
Topic: Central atom and octet rule?
Replies: 12
Views: 1089

### Re: Central atom and octet rule?

Central atoms can have fewer than 8 atoms or more than 8 atoms depending on the circumstances. If an element has access to d-orbitals (group 3 and beyond), then there can be more than 8 electrons on the central atom.
Sun Jun 10, 2018 5:57 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal charge
Replies: 5
Views: 317

### Re: Formal charge

When checking formal charge, bonds count as a single electron if you are not using the equation and just counting, but if you are trying to satisfy an octet, a single bond counts as two electrons for an atom.
Sun Jun 10, 2018 5:54 pm
Forum: Properties of Light
Topic: Wave and Particle
Replies: 10
Views: 636

### Re: Wave and Particle

Light has the characteristics of both a wave and a particle. A photon has a wavelength and also contains energy and can dislodge an electron from an atom with enough energy.
Tue May 29, 2018 5:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone pairs on non-central atoms
Replies: 4
Views: 240

### Re: Lone pairs on non-central atoms

The negative charge of the lone pair electrons result in the repulsion of other electrons in the molecule. The repulsion creates the different bond angles.
Tue May 29, 2018 5:32 pm
Forum: Ionic & Covalent Bonds
Topic: Polar Vs. Non-Polar
Replies: 7
Views: 398

### Re: Polar Vs. Non-Polar

Polarity depends on the electronegativity difference. Ranges 0 - 0.4 is non-polar, 0.5 - 1.7 is polar, 1.7 < is ionic.
Tue May 29, 2018 5:24 pm
Forum: Resonance Structures
Topic: Resonance [ENDORSED]
Replies: 5
Views: 470

### Re: Resonance[ENDORSED]

I'm not entirely sure but I believe the question if asking for the resonance structure with the lowest formal charge.
Tue May 29, 2018 5:20 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: lone pairs
Replies: 3
Views: 173

### Re: lone pairs

The negative charge of the lone pair electrons repulse other negatively charged electrons in a molecule. This repulsion results in the various bond angles of a molecule.
Tue May 29, 2018 5:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond angle
Replies: 9
Views: 421

### Re: Bond angle

The negative charge of lone pair electrons causes repulsion with other electrons. This results in a greater angle in the shape of a molecule.
Tue May 29, 2018 5:15 pm
Forum: Ionic & Covalent Bonds
Topic: Double/Triple Bonds
Replies: 8
Views: 485

### Re: Double/Triple Bonds

Any atom can produce a double or triple bond if it contains enough electrons and if it would reduce the formal charge.
Sun May 20, 2018 3:33 pm
Forum: Ionic & Covalent Bonds
Topic: What do the roman numerals mean?
Replies: 2
Views: 840

### Re: What do the roman numerals mean?

Roman numerals are a part of nomenclature for compounds when an ion can have multiple charges. The Roman numeral shows the charge of the ion.
Sun May 20, 2018 3:30 pm
Forum: DeBroglie Equation
Topic: De Broglie Wavelength on the Midterm
Replies: 4
Views: 357

### Re: De Broglie Wavelength on the Midterm

The information provided was for the deBroglie wavelength. C=(Lambda)(Nu) is also used for things moving at the speed of light.
Sun May 20, 2018 3:25 pm
Forum: Lewis Structures
Topic: Dots vs lines to represent electrons
Replies: 8
Views: 470

### Re: Dots vs lines to represent electrons

Lines should only be used for bonds while dots should only be used for lone pairs that are not bonded to another atom.
Sun May 13, 2018 10:04 pm
Forum: Lewis Structures
Topic: Meaning of chemical bond
Replies: 5
Views: 228

### Re: Meaning of chemical bond

The line in a covalent bond represents a shared atom while a line in an ionic bond represents an atom being borrowed completely.
Sun May 13, 2018 10:02 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: cations
Replies: 5
Views: 314

### Re: cations

Since it is a caption there are more protons than electrons meaning the electrons feel the attraction of the positively charged protons more making the cation smaller.
Sun May 13, 2018 9:57 pm
Forum: Ionic & Covalent Bonds
Topic: cation vs anion
Replies: 14
Views: 1236

### Re: cation vs anion

Cations have positive charges and give an electron while anions are negatively charged and receive an electron.
Sun May 06, 2018 11:49 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Lewis Structure [ENDORSED]
Replies: 7
Views: 399

### Re: Lewis Structure[ENDORSED]

I believe that as long as the valence electrons are correct then the order of the pair of lone electrons doesn’t matter.
Sun May 06, 2018 11:47 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: electron config in the "d" sublevel
Replies: 5
Views: 345

### Re: electron config in the "d" sublevel

I believe that the d subshell must be completely filled first before it can move onto the next one.
Tue May 01, 2018 2:50 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Question 2.13
Replies: 1
Views: 113

### Question 2.13

Is the question asking where the positive lobe, negative lobe, and nodal planes are for the Px-, Py-, and Pz- orbitals? For example, for the Px-orbital the nodal plane is located through the z-plane, the positive lobe is located along the x-axis, and the negative lobe is located along the y-axis.
Sun Apr 29, 2018 5:47 pm
Forum: Properties of Light
Topic: photoelectric effect
Replies: 4
Views: 226

### Re: photoelectric effect

The Photoelectric Effect showed that light acts as both a wave and a particle. Increasing the intensity of the light did not remove an electron but increasing the lights energy did. This showed that each individual photon needs enough energy to remove an electron and the sheer amount of photons will...
Sun Apr 29, 2018 5:38 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Electron configuration
Replies: 8
Views: 328

### Re: Electron configuration

in class we had an example of writing the electron configuration of Calcium and we were able to write it as: [Ar]4s^2... why are we able to use Argon to write the electron configuration? Argon is the noble gas before Calcium. Argon has a full valence shell, so using Argon summarizes the electron co...
Sun Apr 29, 2018 5:32 pm
Forum: DeBroglie Equation
Topic: does everything have a wavelength
Replies: 10
Views: 637

### Re: does everything have a wavelength

Everything has a wavelength, but not every wavelength is detectable. The wavelength is so inconsequential that it cannot be detected.
Sun Apr 29, 2018 5:30 pm
Forum: Student Social/Study Group
Topic: Rieber Vista(Or any of the Riebers') Chem 14A Study Group Fall 2017
Replies: 6
Views: 697

### Re: Rieber Vista(Or any of the Riebers') Chem 14A Study Group Fall 2017

Sun Apr 22, 2018 5:27 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Which Equation Do We Never Use for Light? [ENDORSED]
Replies: 3
Views: 277

### Which Equation Do We Never Use for Light?[ENDORSED]

During Friday's lecture about quantum mechanics, Dr. Lavelle said we should never use a certain equation for light. What is the equation and in what instances do we use it?
Sun Apr 22, 2018 5:20 pm
Forum: Properties of Light
Topic: still don't uderrsatnd what a photon is [ENDORSED]
Replies: 20
Views: 603

### Re: still don't uderrsatnd what a photon is[ENDORSED]

A photon is a packet of light that does not have mass but it does have energy and momentum. A photon also has both wavelike and particle characteristics.
Sun Apr 22, 2018 5:17 pm
Forum: Photoelectric Effect
Topic: Significance of intensity [ENDORSED]
Replies: 7
Views: 354

### Re: Significance of intensity[ENDORSED]

The intensity of light is the amount of photons. That is why making a light more intense will not result in an electron being removed from an atom. Each individual photon needs enough energy to remove and electron.
Sun Apr 15, 2018 7:38 pm
Forum: SI Units, Unit Conversions
Topic: Length Units
Replies: 15
Views: 772

### Re: Length Units

I would use SI units in the answer unless explicitly asked for a specific unit.
Sun Apr 15, 2018 7:36 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Chemical Equations and Combustion
Replies: 7
Views: 498

### Re: Balancing Chemical Equations and Combustion

In a combustion reaction CO2 and H2O will always be a product. From there you will be able to balance the equation like a normal equation.
Sun Apr 15, 2018 7:27 pm
Forum: Properties of Light
Topic: Speed of Light
Replies: 2
Views: 113

### Re: Speed of Light

The value of the speed of light does change depending on the medium it is going through. For example light travels slower in water than in air. A vacuum is an area with no particles. An example of a vacuum is outer space.
Sun Apr 15, 2018 7:25 pm
Forum: Limiting Reactant Calculations
Topic: actual vs. theoretical yield [ENDORSED]
Replies: 6
Views: 744

### Re: actual vs. theoretical yield[ENDORSED]

Theoretical yield is the amount of products the reactants will make under perfect conditions while the actual yield is the amount of products that the reaction produces. The discrepancies are caused by side reactions, reactants sticking to the flask, etc...
Fri Apr 13, 2018 12:49 pm
Forum: Properties of Light
Topic: Speed in vacuum
Replies: 3
Views: 240

### Re: Speed in vacuum

C is a constant that represents the speed of light in a vacuum. Light will constantly travel at this speed, but this is specifically for a vacuum. The speed of light can change through different mediums. An example of this would be the different speed of light traveling through water.
Fri Apr 13, 2018 12:47 pm
Forum: Properties of Light
Topic: Frequency and wavelength [ENDORSED]
Replies: 4
Views: 245

### Re: Frequency and wavelength[ENDORSED]

Wavelength and Frequency do have an inverse relationship. The longer a wave is the less frequently it will repeat itself. If a wave repeats more frequently the length of the wave would be shortened.
Fri Apr 13, 2018 12:44 pm
Forum: SI Units, Unit Conversions
Topic: Sig Figs
Replies: 9
Views: 583

### Re: Sig Figs

I believe that rounding up is correct as long as it is consistent. If the answer is relatively close I don't think there would be a problem.