Question

Which represents a balanced nuclear equation?

a. 23/11 Na ----> 24/12 Mg +1/1 H
b. 24/11 Na----> 24/12 Mg +1/-1 e
c. 24/13 Al ---->24/12 Mg+0/-1 e
d. 23/12 Mg---> 24/12 Mg +1/0 n

Answer 1

Option b, the sum of or the difference of the atomic number and mass must be equal on both sides of the equation. 

Answer 2

Option b:
`^(24)_(11)Na\rightarrow ^(24)_(12)Mg+^(0)_(-1)e`

A nuclear equation is said to be balanced if the sum of the mass number A and sum of the atomic number Z is equal on both sides of the reaction arrow.

In nuclear reaction, atoms are represented as follows:

`^(A)_(Z)X`

Here, A stands for mass number, Z stands for atomic number and X represents the atomic symbol.

a. The nuclear reaction is as follows:

`^(23)_(11)Na\rightarrow ^(24)_(12)Mg+^(1)_(1)H`

Here, sum of mass number and atomic number on left side of the reaction arrow is 23 and 11 respectively.

On right hand side sum of mass number is 24+1=25 and that of atomic number is 12+1=13. Since, both mass number and atomic number are not same, it is not a balanced nuclear reaction.

b. The nuclear reaction is as follows:

`^(24)_(11)Na\rightarrow ^(24)_(12)Mg+^(0)_(-1)e`

Here, sum of mass number and atomic number on left side of the reaction arrow is 24 and 11 respectively.

On right hand side sum of mass number is 24+0=24 and that of atomic number is 12-1=11. Since, both mass number and atomic number are same, it is a balanced nuclear reaction.

c. The nuclear reaction is as follows:

`^(24)_(13)Al\rightarrow ^(24)_(12)Mg+^(0)_(-1)e`

Here, sum of mass number and atomic number on left side of the reaction arrow is 24 and 13 respectively.

On right hand side sum of mass number is 24+0=24 and that of atomic number is 12-1=11. Since, atomic number is not same, it is not a balanced nuclear reaction.

d. The nuclear reaction is as follows:

`^(23)_(12)Mg\rightarrow ^(24)_(12)Mg+^(1)_(0)n`

Here, sum of mass number and atomic number on left side of the reaction arrow is 23 and 12 respectively.

On right hand side sum of mass number is 24+1=25 and that of atomic number is 12+0=12. Since, atomic number is not same, it is not a balanced nuclear reaction.