α-Particles can be detected using
thin aluminium sheet
barium sulphate
zinc sulphide screen
gold foil
How many neutrons are there in nucleus 'X', if it gives 7N14 after two successive - particle emissions ?
7
10
14
09
The energy equivalent to 1 amu., is :
931.1 MeV
1.492 x 1013 erg
1000 J
107 erg
A.
931.1 MeV
From Einstein equation, E = mc2
Energy equivalent to 1 amu
(E)= 1 a.m.u. x (3 x 108 m/s)2
= 1.66 x 10-27 Kg x 9 x 1016 m2/s2
= 14.94 x 10-11 joule
(Kg m2/s2 = joule)
=
= 931.1 MeV
According to Bohr, the angular momentum of an electron, in any orbit, should be :
h/2
nh/2
h/mv
2/nh
Quantum numbers of an atom can be defined on the basis of :
Hund's rule
Pauli's exclusion principle
Aufbau's principle
Heisenberg's uncertainty principle