n
th
αc/n α
e
2
/4πǫ
0
¯hc
x = 0 x = L/n n
th
R
x
2
e
ax
dx =
x
2
a
2x
a
2
+
2
a
3
e
ax
n l m
l
m
s
2p
1
3p
1
n Br
n