M2+ : 1s2 2s2 2p6
3s2 3p6 3d6
M : 1s2 2s2 2p6 3s2
3p6 3d8
Atomic number = 26
Mass number =56
No. of neutrons = 56 -26 = 30
E = hν = hc/λ
=6.626 × 1034 J s × 3 ×108
m s1 / 45 ×109 m
= 4 .42 ×1018 J
Spliting of spectral lines in magnetic field is
called Zeeman effect and spliting of spectral lines in electric field, is
called Stark effect.
n = 6 to n=5
E6 = -13.6 / 62 ;
E5 = - 13.6 / 52
E6 - E5 = (-13.6 /62)
- (-13.6/52)
= 0.166 eV atom-1
E5 - E4 = (-13.6 /52)
- (-13.6/42)
= 0.306 eV atom-1
Assertion : The spectrum of He+ is expected
to be similar to that of hydrogen
Spin quantum number
For the first electron ms = +½
For the second electron ms = -½
Eu : [Xe] 4f7, 5d0, 6s2
Gd : [Xe] 4f7, 5d1, 6s2
Tb: [Xe] 4f9, 5d0, 6s2