Particulate nature of matter 3

CHEMISTRY  SSS1 First Term

WEEK 10

Particulate nature of matter 3

Performance Objectives

The student should be able to:

1. Define isotopy, atomic number, and mass number and solve calculations on them
2. Define relative atomic mass and solve calculations on relative atomic mass.

Content

Atomic number and mass number

Atomic Number

Neutral atoms of an element contain an equal number of protons and electrons. The number of protons determines an element’s atomic number (Z) and distinguishes one element from another. For example, carbon’s atomic number (Z) is 6 because it has 6 protons. The number of neutrons can vary to produce isotopes, which are atoms of the same element that have different numbers of neutrons. The number of electrons can also…