100+ Periodic Classification of Elements Questions and Answers - 3

Question: 11

What is meant by atomic number?

The atomic number of an element is equal to the number of protons in the nucleus of its atom.

Question: 12

What is mass number?

Total number of protons and neutrons in the nucleus is called mass number of the atom.

Question: 13

What is artificial radioactivity?

The transmutation of one element into another by artificial means is called artificial radioactivity or induced radioactivity.