Question

The particle represented by X, in the artificial transmutation ${}_4^{9}Be+X{\to }_3^{6}Li{+}_2^{4}He$ is

• A. Beta particle
• B. Positron
• C. Deuteron
• D. Proton
• E. Alpha particle

Answer 1

The correct option is D Proton

${}_4^{9}Be+X{\to }_3^{6}Li{+}_2^{4}He$

To balance the equation above for mass, charge and mass number, the nucleus $X$ to the left must have atomic number $1$ and mass number $1$; it is therefore also proton.

The sum of atomic numbers of LHS is equal to the sum of the atomic numbers on RHS.

$4+X=3+2\Rightarrow X=5-4=1$

Also, the sum of mass numbers of LHS is equal to the sum of the mass numbers on RHS.

$9+X=6+4\Rightarrow X=10-9=1$

The complete equation therefore reads:

${}_4^{9}Be{+}_1^{1}H{\to }_3^{6}Li{+}_2^{4}He$

In the above equation,

Hence, the equation is balanced and proton is the correct particle.