STANDARDChemistry-Atomic Structure
STANDARD Chemistry Mass Number Calculation MCQ Question
Type: MCQ-numerical-Easy-Class 11
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
Correct Answer
Option D
Detailed Explanation
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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