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
D.
09
The atomic number of radioactive element increases by one by the emission of 1 - particle. Hence, after the emission of 2 -particles, there will be an increase of 2 units in atomic number.
Hence, 5X14 7N14
Hence, the number of neutrons in parent element (X) = 14 - 5 = 9
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