Which metal is used in radiation shielding?

The number of $\alpha$ and $\beta$-particles emitted in the nuclear reaction $_{92}U^{238} \to _{90}Th^{234} \to _{91}Pa^{234}$ are respectively:

In radioactive decay,which one of the following moves the fastest?

$\beta$-particles are emitted from the atom

What happens when an $\alpha$-particle is emitted?

The radiations from a naturally occurring radio element,as seen after deflection in a magnetic field in one direction,are