## Search found 118 matches

Sun Oct 27, 2019 1:04 am
Forum: Sigma & Pi Bonds
Topic: Single vs. Double bonds
Replies: 15
Views: 154

### Re: Single vs. Double bonds

When there is a double bond, there are more electrons being shared between the two atoms, thus the attraction between the nucleus of the atoms (the positively charged regions) are pulling on two negatively charged electrons instead of one. This is a stronger attraction than a single bond with one el...
Sun Oct 27, 2019 1:01 am
Forum: Properties of Light
Topic: Rydberg Equation
Replies: 3
Views: 66

### Re: Rydberg Equation

The constant R in the Rydberg equation can have multiple different numbers depending on the units that it is used in, however in the Rydberg Equation the units Hz is used. The constant that is used in the equation is 3.29 x 10^15 Hz. If you google this constant you might find different numbers but o...
Sun Oct 27, 2019 12:59 am
Forum: Lewis Structures
Topic: Drawing Lewis Structure
Replies: 6
Views: 44

### Re: Drawing Lewis Structure

The reason why you draw the dots (lone pairs) of electrons is because it gives a more clear representation since there are expections to the octet rule. However, in the case for Hydrogen atoms since there are only 2 electrons you won't see any dots, only the single covalent bond.
Mon Oct 21, 2019 11:20 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: 1B. 25
Replies: 2
Views: 50

### Re: 1B. 25

the units are in pm which means that the x would be 350 x 10^-12 m not 10^-10
Otherwise, yes, the other steps you said would be correct
Mon Oct 21, 2019 11:16 am
Forum: Photoelectric Effect
Topic: 0KE electron?
Replies: 2
Views: 48

### Re: 0KE electron?

In the lecture, I believe he explains that this experiment is done with a slightly positively charged detector that, although the electron has 0 Kinetic energy, will slowly draw the electron towards it, away from the atom.
Mon Oct 21, 2019 11:13 am
Forum: Properties of Light
Topic: calculating frequency of light
Replies: 4
Views: 78

### Re: calculating frequency of light

Another keyword in the problem is "the lowest frequency" this means that it is the bare minimum to remove an electron and therefore will not have any excess energy to transform into Kinetic energy and thus Ke = 0
Mon Oct 21, 2019 11:10 am
Forum: Photoelectric Effect
Topic: KE energy & intensity
Replies: 5
Views: 64

### Re: KE energy & intensity

The energy is related to the frequency because of the formula E=hv The intensity of the light only changes how many photons are being released, it does not affect the amount of energy of the photons Thus, you can see the relationship between kinetic energy and the frequency in this equation: Ke= hv ...
Mon Oct 21, 2019 11:06 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: S and P orbital
Replies: 3
Views: 41

### Re: S and P orbital

Also, the only reason that the expectations of Cr and Cu "take" electrons from the S orbital for the D orbital is because of the stability. For instance, in the case of Cr, taking an S electron and putting it into the D subshell makes it so that there is one electron in each of the 5 orbit...
Sun Oct 13, 2019 5:03 pm
Forum: Properties of Light
Topic: 'light intensity'
Replies: 8
Views: 83

### Re: 'light intensity'

So the most important thing to remember is that if a certain wavelength of light does not cause electrons to be emitted, increasing or decreasing the intensity will not change the fact that electrons are not emitted. This is because the relationship between wavelength and energy. The equation E= hv ...
Sun Oct 13, 2019 4:58 pm
Forum: DeBroglie Equation
Topic: Wave properties of electrons
Replies: 3
Views: 64

### Re: Wave properties of electrons

All electrons, protons, and neutrons have wave-like properties. This is because according to the de Broglie equation, all objects with momentum have wave-like properties. However, electrons, protons, and neutrons all have extremely small masses that allow for their wave-like properties to be measured.
Sun Oct 13, 2019 4:54 pm
Forum: Properties of Light
Topic: P.E Experiment
Replies: 2
Views: 27

### Re: P.E Experiment

Also, if the amount of energy from the photon does not exactly match the amount of energy to excite the electron to a new energy level, it will not be absorbed. Even if the energy of the photon is greater, if it is not exact, it will not be absorbed. This is because it can't absorb only part of the ...
Sun Oct 13, 2019 4:53 pm
Forum: Properties of Light
Topic: P.E Experiment
Replies: 3
Views: 58

### Re: P.E Experiment

Absorb and emit are not interchangeable terms. When an electron falls down from a higher energy level to a lower energy level, it will emit specific energy -- the same amount of energy needed to elevate it. For example, if a certain wave length excited an electron from n=2 to n=4, the amount of ener...
Thu Oct 10, 2019 5:43 pm
Forum: Photoelectric Effect
Topic: How the Photoelectric Effect Proves Light is a Photon
Replies: 4
Views: 82

### Re: How the Photoelectric Effect Proves Light is a Photon

From what I understand, the reason why this proves light acts as a photon in this situation is because of the "photon-electron" interaction. The energy of the individual photon must be equal to that of the energy required to have an electron "jump" to a higher energy level. Thus,...
Mon Sep 30, 2019 10:28 pm
Forum: Molarity, Solutions, Dilutions
Topic: G.17 Homework Problem
Replies: 3
Views: 57

### Re: G.17 Homework Problem

What you have to take into account is the new molar mass of the CuSO4*5H20. So what you do is add the molar mass of CuSO4 and the molar mass of 5 H20 molecules and then do the same calculation from part a.
Mon Sep 30, 2019 10:18 pm
Forum: Empirical & Molecular Formulas
Topic: Rounding [ENDORSED]
Replies: 12
Views: 180

### Re: Rounding[ENDORSED]

What I was taught was that in chemistry you always want to make sure you are using the proper sig fig rules and then don't round your answer until the very end of the problem. Waiting to round to the end will prevent the slight rounding difference from each step from adding up into the wrong answer....
Mon Sep 30, 2019 8:29 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Mole ratios
Replies: 4
Views: 102

### Re: Mole ratios

From what I understand, the coefficients mean the ratio between the about of NaCl and H20 is 1 mole to 1 mole. Therefore, in your example, if you have 0.018 moles of NaCl, you would need 0.018 moles of H20 to ensure that there is no limiting reactant. However for example, if it was NaCl + 2H20, you ...
Mon Sep 30, 2019 6:59 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Aqueous Solution
Replies: 6
Views: 87

### Re: Aqueous Solution

It is a liquid when the element is in a liquid form - for example a melted metal is liquid. However, aqueous means it is dissolved in water - for example the salt (NaCl) dissociates and is surrounded by water molecules. And make sure you remember aqueous solutions are only in water.
Mon Sep 30, 2019 6:40 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical Formula [ENDORSED]
Replies: 6
Views: 453

### Re: Empirical Formula[ENDORSED]

I agree with both other answers above, but the way I think about the 100g concept is that rather than the actual mass being 100g, it is a comparison. Because of the mass percentage of an element in a given molecule will be the same whether you have 10g of the molecule or 1000g. Thus, we use an easy ...