CHEM**
posted by K on .
I just have 2 other questions that I just want to make sure on:
Place the following elements in order of decreasing atomic size: tellurium, bromine, argon, cesium, strontium, and selenium. (Te, Br, Ar, Cs, Sr, Se)
~~(or...the correct ranking cannot be determined)~~
I think that the correct answer is:
******* Ar, Br, Se, Te, Sr, Cs ********
Am I correct on this???
One other question to verify:
Which set of quantum numbers is "not" possible?
a) n=2, l=1, ml=0, ms=1/2
b) n=3, l=1, ml=2, ms=1/2
c) n=1, l=0, ml=0, ms=1/2
d) n=5, l=3, ml=2, ms=1/2
***I think that the correct answer, the one that is 'not' possible is "B".
Please let me know if I am correct or not.

I think you have them arranged from smallest to largest; isn't that the reverse of the way the qustion wants them arranged? In the order you list them, the covalent radius, in Angstroms, as given on my periodic table is as follows:
0.98; 1.14; 1.17; 1.36; 1.91; 2.35. 
Ar is before Br is it not?

Likewise, ignore this post. It isn't clear if we are talking about increasing or decreasing.

ignore the "At"...it was supposed to be "Arargon"

You had a post here that has disappeared.
If we go by decreasing size, we start with Cs (the largest) and end up with Ar (the smallest).
Your answer for B is correct. 
Place the following elements in order of Decreasing atomic size: tellurium, bromine, argon, cesium, strontium, and selenium.
would the correct ranking then be:
Cs, Sr, Te, Se, Br, Ar ???
or am I still way off?? 
That looks right to me but confirm it with those numbers I wrote in a previous post. I can't get both on the screen at once so it's difficult to check them.

you have them as: 0.98, 1.14, 1.17, 1.36, 1.91, 2.35
so...does this mean that:
Cs=2.35, Sr=1.91, Te=1.36, Se=1.17, Br=1.14 & Ar=0.98 ???
Therefore this order is then correct, as in being listed in order of Decreasing atomic size?? (this isn't the same as in order of decreasing atomic radius, or is it?..if it is not...I think that's where I messed up before) 
this ordering came up as being correct. Thank you for your time, it's much appreciated!

Decreasing atomic radius means, to me, that we list the lagest radius first and the smallest radius last. That is the way they are listed above which is what the problem asked for. I don't understand why decreasing atomic radius and decreasing atomic size are not the same, at least in respect to this problem. We might think of size as volume but I think the intent in this problem is to use the radius. Generally, larger radius means larger volume. Or said another way, larger radius means the atom occupies more space.

I am going to take the above down. Again, thank you.

C8H8O3 sketch