CHEMISTRY COMMUNITY

Mauricio Maravilla 3C

Waking up early every day!

Mauricio Maravilla 3C

Since the 3- ion has 3 extra electrons, the nucleus has a weaker pull on all of its electrons whereas the ion with 2 extra electrons has more control over its electrons. This can get pretty tricky though, especially if the question is asking about more than one type of element.

Mauricio Maravilla 3C

In terms of mere electronegativity some teachers say that if the difference is less than 0.5 or 0.4, the molecule is non-polar. You also have to pay attention to things such as symmetry, what types of atoms it's bonded to, but It's pretty simple to determine if a bond is polar.

Mauricio Maravilla 3C

E=hv is used when you are trying to find wavelength, frequency, and energy of a photon. 1/2 mv^2 is going to be used when were dealing with electrons that have ejected from an atom as a result of a photon. I think you can do this with any object as well. Maybe not idk.

Mauricio Maravilla 3C

Just divide the total energy by Avogadro's number since you can assume all of the photons have the same frequency. I'm guessing the problem is talking about intensity, otherwise it wouldn't make sense to have a mole of photons. But after this it's just a simple plug and chug Planck's Constant and yo...

Mauricio Maravilla 3C

Joules per photon would be if the question is talking about an incoming light source and joules per atom probably refers to the energy released by each atom when light excites it. Hope this helped

Mauricio Maravilla 3C

Thanks!

Mauricio Maravilla 3C

If it can accept more than one proton

Mauricio Maravilla 3C

Want to hear a joke about nitrogen oxide?

Mauricio Maravilla 3C

I was pretty sure I was failing... then I read this.

Mauricio Maravilla 3C

Usually you will see Sulfur and Phosphorus forming expanded octets, and sometimes it can be some of the halogens, and even noble gases. The best way to figure out if something has an expanded octet is to try and draw it's Lewis structure.

Mauricio Maravilla 3C

Thanks Dr. Lavelle!

Mauricio Maravilla 3C

Does anyone know if 14B covers radioactivity?

Mauricio Maravilla 3C

Does anyone know how noble gases were experimentally proven to not have any electron affinity. Again, experimentally, not conceptually.

Mauricio Maravilla 3C

Thanks for the response!

Mauricio Maravilla 3C

Thanks I needed this!

Mauricio Maravilla 3C

Uranocene was the the molecule with the highest coordination number I found. It has a coordination number of 16, so it probably has a large number of electrons on the central atom (uranium).

Mauricio Maravilla 3C

On one of the HW assignments I have to arrange aqueous solutions (assuming equal concentration) of various acids and bases according to the pH scale. I know HF is a weak acid since it doesn't disassociate completely but it should still have the lowest pH if it's aqueous correct? So I guess I'm askin...

Mauricio Maravilla 3C

If NH3 is amphoteric, and I have to put it in an answer box which have strong/weak acids/bases and neither, would it go in neither?

Mauricio Maravilla 3C

I understand how hybridization can help us visualize the geometry of molecules, but what else does it say about a molecule?

Mauricio Maravilla 3C

HF doesn't completely dissociate cause of how intensely the fluorine bonds to the hydrogen. As a result, the solution that it is supposed to be dissolved in is not acidic, or best case weakly acidic.

Mauricio Maravilla 3C

Mauricio Maravilla 3C

Trigonal Pyramidal is the shape of a central atom that has 3 atoms bonded to it and one lone pair, while the seesaw shape forms when a molecule has one electron pair with 4 atoms bonded to the central atom.

Mauricio Maravilla 3C

What time is the Final on Sunday?

Mauricio Maravilla 3C

Both melting point and boiling points are related to IMF's and IntraMF's

Mauricio Maravilla 3C

Strong acids/bases end up creating neutral solutions because they disassociate almost completely. This creates a neutral pH level whereas weaker acids/bases do not always dissociate completely resulting in a solution that can be somewhat acidic or basic. hope this helped.

Mauricio Maravilla 3C

Some metal oxides react with water to form alkaline solutions, and some metal oxides don't react at all with water. Other then that, the majority of metal oxides form bases when reacted with water.

Mauricio Maravilla 3C

Do we have to remember Ryberg's constant for different units?

Mauricio Maravilla 3C

Thanks for all the helpful answers!

Mauricio Maravilla 3C

When solving photoelectric effect problems, when is the energy of the atom negative or positive. I know it has to do something with going from lower to higher energy levels, vice versa.

Mauricio Maravilla 3C

I have another question, if a problem gives us the speed for example of an electron, we can get the momentum since we know what the mass of an electron is. Do we then multiply delta x by the momentum, since the uncertainty in its momentum is 100% which is just one?

Mauricio Maravilla 3C

Do we need to memorize the strong/weak acids and bases. For the most part I have em down, but I just want to make sure. Thanks

Mauricio Maravilla 3C

Will sig figs be important on the final?

Mauricio Maravilla 3C

Thank you for this! This really answers some of the questions I had about being a pre-med student.

Mauricio Maravilla 3C

triamminetrichlorocobalt(III)... Hopefully something like this isn't on the final.

Mauricio Maravilla 3C

Why don't noble gases have electron affinities? I know they already have full octets, but is it possible to add an electron to a noble gas, since there are compounds that form expanded octets, such as XeOF2?

Mauricio Maravilla 3C

Theoretically, do London Dispersion forces exist at the absolute 0. (0 Kelvins) What if we got lucky enough and the electron's were arranged in a way that they were as polar as London Dispersion forces get??? Thoughts?

Mauricio Maravilla 3C

I was watching one of the lectures on IMF's, and I started thinking. Salt dissolves in water because the hydrogen bonds split the NaCl bonds into ions giving us Na+ ions, some HCl, and some OH- ions. But what happens if you were to heat up salt to its melting point. Does the NaCl disassociate into N...

Mauricio Maravilla 3C

Lewis Acids are the atoms or molecules that can accept a lone pair of electrons while Lewis bases are those that can "donate" a lone pair of electrons. The word donate is a little misleading as when these compounds exchange the electrons the result is a coordinate covalent.

Mauricio Maravilla 3C

When you write out the Lewis structure for a molecule that has a coordinate covalent bond, do you have to specify that it is a coordinate covalent bond, and do you have to explain where the lone pair of electrons are coming from?

Mauricio Maravilla 3C

What does it mean when a question asks what resonance structure is the most plausible? I know it has to do something with having formal charges that are as close to 0 as they can be, but I'm still not sure.

Mauricio Maravilla 3C

Yeah so for those compounds dipole-dipole moments occur because the C-Cl bonds are polar covalent, where Cl is more electronegative that carbon. This means that Cl will hog the electrons creating a partial negative charge on it. When one of these C-Cl bonds interacts with another C-Cl bond from anot...

Mauricio Maravilla 3C

When radicals react with other elements or compounds, do they behave like ionic compounds since the radical does not prefer to have a lone electron?

Mauricio Maravilla 3C

Does anyone know if E(excess) is the same thing as the kinetic energy of the electron?
Thanks

Mauricio Maravilla 3C

I had a question about the unit S^-1 or 1/seconds
I remember reading that when you have those units it is equal to hertz or joules.
1/seconds = 1 Hz or 1/seconds = 1 Joule

Can someone let me know which one it is?
Thanks

Mauricio Maravilla 3C

Are we going to review the midterm 1 answers before or after grades are turned in?

Mauricio Maravilla 3C

805377003 wrote:When do we find out our midterm grades?

Dr. Lavelle put out the grades earlier today!

Mauricio Maravilla 3C

Will there be a meeting / lecture showing us how to do the problems for midterm 1? I want to see which problems I did incorrectly.
Thanks.

Mauricio Maravilla 3C

Okay then, so I was working on a Heisenberg's Indeterminacy question and the one thing from preventing me from the answer were the units of conversions. I needed to get my answer in meters per second but I kept getting it in ( Joule-Seconds ) / ( meters * kilograms ) After looking around on the inte...

Mauricio Maravilla 3C

I have been looking around trying to figure out how to get points for this website and nobody has given me a helpful answer. I tried asking my TA but I didn't really get an answer, I sent a message via this website 2-3 weeks ago but got no response. It is currently week 5 so I guess my grade is abso...

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