⋄
⋄
⋄
⋄
⋄
n
th
αc/n
α
e
2
/
4
π
ǫ
0
¯
hc
x
=
0
x
=
L/n
n
th
R
x
2
e
ax
dx
=
x
2
a
−
2
x
a
2
+
2
a
3
e
ax
n
l
m
l
m
s
2
p
1
3
p
1
n
B
r
−
n
