- Bi-metallic strips are used in electric iron and fire alarms.
- Thermometers have mercury or alcohol inside them. It works on the “Principle of Expansion”.
- Atom may or may not exist in Free State.
- Molecules exist in Free State.
- Molecule is a combination of two or more like and unlike atoms.
- Element is the pure form of the matter.
- Element is compound of only one kind of atoms.
- Total elements are 118. There are 92 in nature while the remaining elements are man-made.
- Out of 118 elements, 20 elements are classified as non-metals.
- Hydrogen is used for filling of weather balloons.