Lesson: Atomic and Mass Numbers

In this lesson, we will learn how to define and calculate the atomic and mass numbers of elements based on their positions in the periodic table.

Worksheet: 14 Questions

Q1:

An atom of calcium has a mass number of 42 and an atomic number of 20. How many neutrons are there in its nucleus?

Q2:

An atom of chlorine has a mass number of 35. What is the total number of protons and neutrons in its nucleus?

Q3:

An atom of sulphur has 16 protons in its nucleus. What is the atomic number of sulphur?

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