Question

The atomic number of an atom is 30 and its mass number is 60. Which of the following is correct?

• A. Number of electrons = 30
• B. Number of protons = 39
• C. Number of neutrons = 29
• D. Number of neutrons = 19

Answer 1

The correct option is A Number of electrons = 30

Given that,
Atomic number = 30 and Mass number = 60
We know that,
Atomic number = number of protons = number of electrons = 30
Also,
Number of neutrons = mass number - atomic number = 60 - 30 = 30