When a uranium isotope ${ }_{92}^{235} U$ is bombarded with a neutron, it generates ${ }_{36}^{89} Kr$, three neutrons and:

Assertion: ${}_Z{X^A}$ undergoes a $2\alpha  -$ decays, $2\beta  -$ decays and $2\gamma  - $ decays and the daughter product is ${}_{Z - 2}{X^{A - 8}}$

Reason : In $\alpha  - $decays the mass number decreases by $4$ and atomic number decreases by $2$. In $2\beta  - $ decays the mass number remains unchanged, but atomic number increases by $1$ only.

Assertion : Radioactive nuclei emit ${\beta ^ - }$ particles.

Reason : Electrons exist inside the nucleus

Given the masses of various atomic particles $m _{ p }=1.0072 u , m _{ n }=1.0087 u$ $m _{ e }=0.000548 u , m _{ v }=0, m _{ d }=2.0141 u$ where $p \equiv$ proton, $n \equiv$ neutron, $e \equiv$ electron, $\overline{ v } \equiv$ antineutrino and $d \equiv$ deuteron. Which of the following process is allowed by momentum and energy conservation $?$

Assertion : Cobalt $-60$ is useful in cancer therapy.

Reason : Cobalt $-60$ is a source of $\gamma  - $ radiations capable of killing cancerous cells

If Alpha, Beta and Gamma rays carry same momentum, which has the longest wavelength