[Bboy Stan]

1. Write the electron configuration for the third-period elements Al, Si, P, S and Cl. Is there a relation between the group number of each element and the number of electrons in the outermost energy level?

2.Write the noble gas notation for the elctron configuration of each of the following elements:
a. As
b. Pb
c. Lr
d. Hg
e. Sn
f. Xe
g. La


Please write an explanation on how you did it and what not.

[joolee.]

I thought that there was a separate section for homework help?

Sorry I'm not much help.

[Bboy Stan]

They removed it a while ago..so I'm not sure where this goes..

[fallenbroke]

1) Electronic Configuration

Al ; (2,8,3)
Si ; (2,8,4)
P ; (2,8,5)
Cl ; (2,8,7)

Relationship : The number of outshell (valence) electrons has the same value of that of it's group . Meaning , Al is in group III thus it has 3 valence electrons . It goes the same for Si which is in group IV , P which is in group V and Cl which is in group VII respectively .

2 ) Noble Gas Electronic Configuration

I don't really understand the question . Does it mean to give the nearest noble gas electron configuration ? If it is , just look at the periodic table and locate the nearest noble gas . And then that will be the electronic configuration . ( But yes , I'm not sure , erm , so ask someone else ! Sorry ! )

Little things that you should know about Nobel Gases ;

Noble gases exist in duplet or octet structure . Meaning , it has an electronic configuration which ends with a (2) like Helium , or it ends with (...8) like Neon , Argon , Krypton , Xenon or Radon .

Noble gases can be found in Group 0 . Because of their duplet or octet structure , they are very stable .


Hmmmm , yeah . That's all I suppose . If there's anything else , do feel free to PM me !

P.S. Hmmmm . Right , I'm really not sure now . Uruchai's way of writing the electronic configuration is different ! Lol . I think my country's using a different system . But yeah that's how we do it here . Sorry if I wasn't of any help !

[uruchai]

I'm just gonna help you with one or two and I hope you'll be able to figure out from there...

1. electronic configuration for Aluminum [Al]. the atomic number is 13:
Al = 1s^2 2s^2 2p^6 3s^2 3p^1

---> ^ = indicates notation. when writing it, dont use that symbol. write it as if you're writing 1s "to the power of" 2. also, this is the number of electrons you fill in the subshell. so basically, you need to know the atomic number in order to get the configuration.
[s-subshell can fill a max of 2 electrons; p = 6; d = 10, f = 14]. so if you count the bolded digits, it all adds up to 13, which is Al's atomic number.

I hope this is not confusing. im not good with explaining these stuff.

2. basically for noble gas notation, you look at the configuration of a noble gas closest to the given element. noble gases are He, Ne, Ar, Kr.
so, let's take As. it has an atomic # of 33. the one closest to that is Ar with an atomic # of 18. so the noble gas notation would be:

As = [Ar] 3d^10 4s^2 4p^3

hope that kinda helps. btw, follow the Aufbau Principle when writing electron configuration. just google it and there's tons of pages about it.

[Vino de Jerez]

you really need a periodic table huh. its much easier. then u calculate. haha okay i know im not helping. but im just to lazy to do. so sorry!

[asian amy]

I'll explain the noble gas one even though I suck at explaining.

So pretty much you kinda just count across to figure out the electron configuration. So for example, for F, which is 2nd to last at the end in the 2nd row, it would be 1s^2 2s^2 2p^5. You find the exponent by counting how many boxes over the element is in its group. For noble gas notation, you would use noble gases as a bookmark for the element you are solving for. So for As, the closest noble gas before it is Ar. So you would write the noble gas to represent the its electron configuration, and add on the necessary parts to make it As. So it would look like [Ar]4s^2 3d^10 4p^3. I think this is what the question is asking... I would refer to the book for the conceptual part of it so you can actually understand how it works.