Dr. Collins chemistry problem help

[Member20192019]

Yttrium's electronic configuration is [Kr](5s)^2(4d)^1. What is the common ion charge exhibited by yttrium?

The answer Collins gives is +3. Can anyone explain this? Should yttrium lose only the two 5s electrons because those are the valence electrons?

 

[Verduchi]

Look at atomic number of Ytrium (39) and look at it's noble gas atomic number which in this case is Kr (36)

 

[Member20192019]

Do you always look at the closest noble gas and subtract electrons until you get to the noble gas?

 

[Verduchi]

For these types of questions always look at the noble gases in the previous row( ex: for Fe you would use Ar) then subtract the electrons.

 

[mehari]

Yttrium's electronic configuration is [Kr](5s)^2(4d)^1. What is the common ion charge exhibited by yttrium?

The answer Collins gives is +3. Can anyone explain this? Should yttrium lose only the two 5s electrons because those are the valence electrons?

it is obvious to know upto the noble gas and forget it as it doesnt help u on such questions, to identify valence electron or group, metals are filled in S and nonmetals S and P, then transition metals filled the S and D. So if it is metal u will see the last electron conf, S maybe having 1 or 2 electron/s, in nonmetals the P orbital partially start filled from 1 to 5, and if filled with 6 while last orbit it is noble gas. in the transition metals, u see D is filling and then add the D electrons to the 2 electrons from the S, then that is the valence electron. so it is obvious 2 + 1 = 3 for ur question.
hopefully it helps u