Which of the following is a common use of a neutron in nuclear applications?

The age of the most ancient geological formations is estimated by:

Bombardment of aluminum by $\alpha$-particle leads to its artificial disintegration in two ways,$(i)$ and $(ii)$ as shown. Products $X,$ $Y$ and $Z$ respectively are,

The hydrogen bomb is based on the principle of:

According to the nuclear reaction $_4Be + _2He^4 \to _6C^{12} + _0n^1$,what is the mass number of the $Be$ atom?

$_{98}Cf^{246}$ was formed along with a neutron when an unknown radioactive substance was bombarded with $_{6}C^{12}$. The unknown substance was: