Which of the following statements about applying Slater's rules are correct?

AEach $4 s$ electron screens a $3 d$ electron by $0.35$ .
BFor a $4 p$ electron, each electron of the $3 d$ subshell contributes $0.85$ to the screening constant.
CFor a $3 d$ electron, each electron in the $3 s$ and $3 p$ subshells contributes $1.00$ .
DFor a $2 p$ electron, each other electron of the $2 s$ or $2 p$ subshell contributes $0.30$ .

Answer: B, C

For an

n p

electron the

(n - 1)

shell gives

0.85

each, so the first statement is true. For an

n d

electron every electron in groups to the left gives

1.00

, so the second is true. The same-group value is

0.35

(only

1 s

uses

0.30

), and groups to the right (such as

4 s

for a

3 d

electron) contribute

0