2004 AIPMT NucleiComposition of Nucleus Easy Question 1 of 2 in Composition of Nucleus

A nucleus represented by the symbol $^{A}_{Z}X$ has :-

A Z protons and A – Z neutrons
B Z protons and A neutrons
C A protons and Z – A neutrons
D Z neutrons and A – Z protons

The answer is A.

Solution

In the symbol $^{A}_{Z}X$:
Z = atomic number = number of protons in the nucleus.
A = mass number = total number of nucleons (protons + neutrons).
So the number of neutrons $N = A - Z$.
Hence the nucleus has Z protons and $(A - Z)$ neutrons.

Concept Atomic number and mass number

Composition of Nucleus in past papers

2 questions from this chapter have appeared across 2 exam years.