MCQ
Isotopes of an element contain:
- ✓The same number of protons but different number of neutrons.
- BThe same number of neutrons but different number of protons.
- CEqual number of protons and electrons.
- DEqual number of nucleons.
✓
Answer
Correct option: A.
The same number of protons but different number of neutrons.
Isotopes of an element must have same atomic number $(Z)$ but different mass number $A.$
Number of protons is equal to the atomic number.
So, isotopes of an element have same number of protons.
Mass number is equal to the sum of number of protons and neutrons i.e. $A = p + n$
As isotopes of an element have different mass number but same number of protons, thus they must have different number of neutrons.
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