Question

A nucleus X has a mass number 12 and atomic number 6. Calculate the number of neutrons and protons, when the nucleus X loses :
(a) One proton
(b) One neutron.
Write the changes in symbolic form.
[4 MARKS]

Answer 1

Each Part: 2 Marks

Atomic number = Number of protons
Number of protons = 6
Number of neutrons
= Mass number - Number of protons
= 12 - 6 = 6
Element X can be written as ${}_6^{12}X$
(a) Whne the element X loses one proton
${}_6^{12}X{\to }_5^{11}Y{+}_1^{1}P$

(b) When the element X loses one neutron
${}_6^{12}X{\to }_6^{11}X{+}_0^{1}n$