Quantum Numbers

In this video, I define the 4 quantum numbers and then show you how to find these numbers for the electron of highest energy in an atom. This is a basic quantum numbers lecture, NOT anything advanced.

Category:

Education

Tags:

• quantum
• chemistry

[mrfantastik7]

Question from NYC: how do you know how many spots or "blanks" there are? in one of the examples for a "d" electron, you made 5 blanks. what is a quick way to know how many there are?

[melanieharlan]

@mrfantastik7 Because each "blank" represents an orbital and there are 2 electrons per orbital, you can remember how many blanks by taking the number of electrons in that sublevel and dividing by 2. To remember how many electrons in the sublevel, just count the # of elements in that particular row in the sublevel (ex. for 3d, count from Sc to Zn: 10 elements represents 10 electrons, 10/2 = 5 orbitals or "blanks")

[Miguelyou2]

@melanieharlan is it possible to find the element by quantum numbers? like this one (4, 2, 1, +½). thanks..

[melanieharlan]

@Miguelyou2 you betcha! As long as you know that the 4Q#'s are from the last electron in an atom, you can ID the element. 4=energy level, 2=d-block, 1=4th orbital, +1/2=up arrow, so your element would be the 4th element in 4d or Mo. You just have to work backwards...

[gvsfgdf]

Quantum numbers?? what are theyyy??? Wellll.....WHO WANTS TO SOLVE THE TIME-DEPENDENT SCHRODINGER'S EQUATION for multi-electron atoms?? :DDDD *crickets* fine then..... lol

[melanieharlan]

@gvsfgdf HAHAHAHAHAHA!!! OMG, this totally made me crack up in front of my class. They all just looked at me like I was crazy. Then I tried to explain why I was laughing and they REALLY looked at me like I was crazy. Oh well, crazy chemistry teacher it is :P

[dafinaiscool]

YOU JUST SAVED MY CHEM GRADE! Thank you sooo much!

[landroverspike1990]

thanks so much this is so helpful

student grd 12 chem



[mysstring1]

-why do we place one upward arrow into each blanks (until every blank occupies one) before we fill in the blanks with the second electron pointing downwards?

-what does it mean by s have 1 orientations and p has 3, d has 5, f has 7? how is it different to the number of subshells /orbitals with each principle energy level?

-how do electrons travel in reality? are they paired up with physical bonds or just some sort of attractions?

[MsCindy45]

May God bless you! I got it. The chem teacher I got needs to throw in the towel. Smart , but burnt out.

[happypenguin64]

Yes! This will help me in my final. Thank you!!!

[psp892081]

thank u very much

[sandrinekows]

THANK YOU . WHY DO I GET IT NOW UST BEFORE MY EXAM ON TUESDAY!