The elements in the periodic table are classified as metals and non-metals based on their physical and chemical properties. There are around \(95\) metals and \(17\) non-metals in the periodic table.
Metals are electropositive elements where they donate electrons to form a stable configuration.
Physical properties of Metals:
A physical property can be observed and measured without altering the sample's chemical identity. In other words, a physical property can cause a physical change but not a chemical change.
Let us see some of the physical properties of metals:
- Melting point and boiling point
Most of the metals are solid at room temperature except mercury which is liquid at room temperature.
Gold and silver
Metals are lustrous (shining or the reflecting nature of metals) in nature. For example gold and silver.
Metals are malleable (as they can be drawn into thin sheets) in nature.
Thin sheet of metals
Metals are ductile (as they can be drawn into wires) in nature.
All metals are hard except sodium and potassium.
Hardness of metal
Metals have \(1\) to \(3\) electrons in the outermost shell.
Electron configuration of sodium metals
Metals are good conductors of heat and electricity (they have free electrons in their outermost shell).
Conduction in metals
Metals have a high density (mass of a unit volume of a material substance).
High density of metals
Metals are sonorous (they produce a ringing sound when struck hard) in nature.
Melting and Boiling Points:
Metals have high melting and boiling points because of their strong metallic bonds, except sodium and potassium, which have low melting and boiling points.
Gold on melting
The materials which generally possess the above properties are called Metals.
Iron, copper, aluminium, calcium, magnesium, gold, silver etc.