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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.
Non-Metals are electronegative elements where they gain electrons to form a stable configuration.
Physical properties of non-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's see some of the physical properties of non-metals.
• State
• No- Lustre
• Non- Malleability
• Non- Ductility
• Hardness
• Valency
• Conduction
• Density
• Sonorous
• Melting and Boiling Points
State:

Most of the non-metals exist in all three states of matter at room temperature. For example, carbon (solid), bromine (liquid) and chlorine (gas).

Lustre:

Non-metals have no lustre in nature (as they have no metallic lustre and do not reflect light) except iodine, diamond.
Note: Diamond is a non-metal which is hard and lustre.
Malleability:

Non-metals are non-malleable in nature (as they are very brittle, they cannot be drawn into sheets) except carbon.

Ductility:

Non-metals are non-ductile in nature (as they are very brittle, they cannot be drawn into wires.)

Hardness:

Non-metals are soft except diamond.

Valency:

Non-metals have $$4$$ to $$7$$ electrons in the outermost shell.

Conduction:

Non-metals are poor conductors of heat and electricity except graphite.

Density:

Non-metals have low density.

Sonorous:

Non-metals make a dull sound.

Melting and Boiling Points:

Non-metals have low melting and boiling points except sodium and potassium, which has a low melting and boiling points.
The materials which generally possess the above properties are called Non-metals.
Example:
Oxygen, carbon, sulfur, hydrogen, phosphorous, nitrogen, chlorine etc.