a) Deduce the expression, N = N0 e−λt, for the law of radioactive decay.
(b) (i) Write symbolically the process expressing the β+ decay of 
. Also write the basic nuclear process underlying this decay.
, an isotope or isobar?
As per the law of radioactive decay, we have
where,
N = Number of nuclei in the sample
ΔN = Amount of nuclei undergoing decay
Δt = Time taken for decay
So,
where λ is Decay constant or disintegration constant.Δt = 0
(b)
(i) The β+ decay for is given below:
A proton is converted into neutron if, the unstable nucleus has excess protons than required for stability.
In the process, a positron e+ (or a β+) and a neutrino ν are created and emitted from the nucleus.
p → n + β+ + ν
This process is called beta plus decay.
(ii) The nucleus so formed is an isobar of 
because the mass number is same, whereas the atomic numbers are different.
