Question
For which one of the following sets of four quantum numbers, an electron will have the highest energy?
|
$$n$$ |
$$l$$ |
$$m$$ |
$$s$$ |
| (a) |
3 |
2 |
1 |
$$\frac{1}{2}$$ |
| (b) |
4 |
2 |
-1 |
$$\frac{1}{2}$$ |
| (c) |
4 |
1 |
0 |
$$ - \frac{1}{2}$$ |
| (d) |
5 |
0 |
0 |
$$ - \frac{1}{2}$$ |
A.
(a)
B.
(b)
C.
(c)
D.
(d)
Answer :
(b)
Solution :
$$\eqalign{
& {\text{For}}\,\,n = 3,\,l = 2\,{\text{the subshell is}}\,\,3d\left( {n + l = 5} \right) \cr
& n = 4,l = 2\,{\text{the subshell is}}\,\,4d\left( {n + l = 6} \right) \cr
& n = 4,\,l = 1\,{\text{the subshell is}}\,\,4p\left( {n + l = 5} \right) \cr
& n = 5,\,l = 0,\,{\text{the subshell is}}\,\,5s\left( {n + l = 5} \right) \cr} $$
According to $$(n + l)$$ rule greater the $$(n + l)$$ value, greater the energy that is 6.