Question

The radioactive isotope D decays according to the sequence

If the mass number and atomic number of D₂ are 176 and 71 respectively, what is (i) the mass number (ii) atomic number of D?

Answer 1

An alpha (α) particle is a helium nucleus (`""_2^4He)`and a beta-minus decay (β⁻) is an emission of an electron.

The substance D₂ can be represented as `""_71^176D_2`.

Hence,

(i) The mass number of D is 180.

(ii) The atomic number of D is 72.