When a radioactive substance emits an $\alpha$-particle,its position in the periodic table is lowered by

In the nuclear decay sequence given below:
$_Z{X^A} \to {}_{Z + 1}{Y^A} \to {}_{Z - 1}{K^{A - 4}} \to {}_{Z - 1}{K^{A - 4}}$
the particles emitted in the sequence are:

In $\beta^-$ decay,which of the following statements is true regarding the daughter nucleus compared to the parent nucleus?

Which of the following is deflected by an electric field?

$A$ radioactive element emits two $\beta$-particles and one $\alpha$-particle. The resulting daughter nucleus is ...

$A$ radioactive reaction is $_{92}U^{238} \to _{82}Pb^{206}$. How many $\alpha$ and $\beta$ particles are emitted?