Standard Books Chemistry Mass Number Calculation MCQ Question with Solution

The number of electrons and neutrons of an element is 18 and 20 respectively. Its mass number is

A

17

B

37

C

2

D

38

Option D

The mass number is the sum of protons and neutrons. Since the number of protons equals the number of electrons (18), the mass number is 18 + 20 = 38.

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STANDARD Chemistry Mass Number Calculation MCQ Question