Question

8. Radioactive decay is accompanied by a change in the mass number, a change in the atomic number, a change in both, or a change in neither. For the following types of radioactive decay, which change(s) do you expect? a. alpha emission b. beta emission c. gamma emission

Answer 1

Answer: a. alpha emission : atomic number decreases by 2 units and mass number decreases by 4 units.

b. beta emission : atomic number increases by 1 unit and mass number remains same.

c. gamma emission : atomic number and mass number both remain same.

Step-by-step explanation:

1. Alpha emmision: In this process, alpha particles is emitted when a heavier nuclei decays into lighter nuclei. The alpha particle released has a charge of +2 units, thus atomic number decreases by 2 units and mass number decreases by 4 units.

`_Z^A\textrm{X}\rightarrow _(Z-2)^(A-4)+_2^4\alpha`

2.)Beta-emmision: In this process, a neutron gets converted into a proton and an electron releasing a beta-particle. The beta particle released carries a charge of -1 units, thus atomic number increases by 1 unit and mass number remains same.

`_Z^A\textrm{X}\rightarrow _(Z+1)^A\textrm{Y}+_(-1)^0\beta`

3.) Gamma ray emission: in this process, an unstable nuclei gives off excess energy by a spontaneous electromagnetic process and releases
`\gamma -radiations`. These radiations does not carry any charge and are electrically neutral, thus atomic number and mass number both remain same.

`_Z^A\textrm{X}^*\rightarrow _Z^A\textrm{X}+_0^0\gamma`