Question

I really need help with the sublevels and orbitals of atoms... Do any of you know any good resources that explain them well? I've watched several videos, but I'm still being stumped by some of my online homework.
For instance, this asks, "how many electrons are in 5s Rubidium"
I answered with 2 because I thought s orbitals hold 2 electrons, but it was incorrect.
Also, I know this is an ion problem, but another question asked me to give the symbol of [Ar] 4s1.3d5 .. The answer is Cr, but I don't understand why.
Also it asks how many electrons in 4f gold. Answer is 14, but I don't get why

Answer 1

Before I say more, I need to confirm something: what level are you in?

Answer 2

I'm taking a college-level Chemistry class.

Answer 3

Hmm are you doing the spdf orbital thingies then?

Answer 4

I think so..
I understand electron configuration perfectly fine, but these types of questions concerning orbitals and sublevels confuse me ; __;

Answer 5

Yeah I didn't take higher level chemistry. I suggest https://www.khanacademy.org/science/chemistry/orbitals-and-electrons/v/orbitals
You will want to explore the site. He has a lot of videos.

Answer 6

Thanks for the resource, I'll try it out.

Answer 7

You're welcome

Answer 8

For your question of the 5s electrons in Rubidium, Rb is in group 1, so it only has 1 electron in its 5s orbital.

Answer 9

If it asked for the 5s electrons in Sr, that would be 2. Make sense?

Answer 10

Also, [Ar] 4s1 3d5 isn't an ion problem, but it is an exception. Cr's 3d sublevel "borrows" an electron fro the 4s sublevel. There are se exceptions in the transition metals you just have to remember. Cr is one, Cu is another.

Answer 11

*There are some exceptions

Answer 12

Aah, okay. So basically since it's 4s1 and not 4s2, it has to borrow one and that's why it's Cr. I get that. But I'm still confused with the 4f gold question..

Answer 13

Great! For Au, 4f sublevel fills before 5d, so it is completely full.

Answer 14

Since Au is in the 5d sublevel

Answer 15

I'm sorry, I'm still having a bit of trouble piecing it together.. I realize that the d block is always one behind and the f block is always two behind, but for some reason, I'm still confused with this one.

Answer 16

Right, so period 6 fill in the order 6s, 4f, 5d 6p. Au is in 5d.

Answer 17

And that statement is an oversimplification, because there are exceptions.

Answer 18

Hmm, I will continue to process that information. I guess my problem is that like the previous question I hadwith 5s Rubidium, you said it has 1 electron, and that makes sense... So my mind wants to say that Au has 9 electrons..

Answer 19

Because of its place on the table.

Answer 20

Anyways, thank you both for the help! I'll figure it out or ask my professor tomorrow. I appreciate it ^ ^

Answer 21

Ok, that would be true if it were asking for the 5d electrons for Au (and if Au weren't an exception)

Answer 22

Glad I could help some. And this might help some too. http://periodictable.com/Properties/A/ElectronConfigurationString.an.html