Introduction

We know that anything that has weight and can occupy space is called matter. Every substance or material is matter because they have weight and can occupy space, but have you ever thought of what makes up or inside substances and materials? Some 2500years ago, a scientist called Democritus believed that if he divided a substance or a material into smaller parts, then he also divided each smaller part again and over again, he would get to a point where he would have a tiny part that could no longer be broken down further are too small for the eyes to see. But, the interesting thing here is that, it is these tiny particles that come together to make a whole material or substance that can be seen by the eye and felt by touch. A particular material or substance may have the same kind of these particles. Meanwhile, other materials or substances could have different kinds of these particles. Any material or substance that has particles of one kind is called an element. There are other substances or materials around us that are made up of different kinds of atoms. These substances are made up of different elements combined together. This is known as compounds.