JSS 1: NON-METALS

Non-metals are elements that ionize by electron gain.

They are usually poor conductors of heat and electricity, brittle, and often exist as gases, liquids, or dull solids at room temperature.

Examples of Non-Metals

Some common non-metals include:

I. Hydrogen (H)

II. Oxygen (O)

III. Nitrogen (N)

IV. Carbon (C)

V. Sulphur (S)

VI. Phosphorus (P)

VII. Chlorine (Cl)

VIII. Fluorine (F)

IX. Iodine (I)

X. Bromine (Br) etc

      Physical Properties of Non-Metals

1. Non-metals are brittle when solid (i.e. they break easily).

2. They are poor conductors of heat and electricity (except graphite).

3. They usually have low melting and boiling points.

4. Many are gases at room temperature (e.g., oxygen, nitrogen).

5. Solid non-metals are dull in appearance (not shiny).

6. They have low density (i.e. light in weight).

7. They are non-sonorous (do not produce ringing sound when hit).

 Chemical Properties of Non-Metals

1. Non-metals gain electrons to form negative ions (anions).

Example: Cl + e⁻ → Cl⁻

2. They react with metals to form ionic compounds.

Example: 2Na + Cl₂ → 2NaCl

3. They react with hydrogen to form gaseous compounds.

Example: H₂ + Cl₂ → 2HCl

4. Many non-metals react with oxygen to form acidic oxides.

Example: C + O₂ → CO₂

SO₂ + H₂O → H₂SO₃ (sulphurous acid)

5. Non-metal oxides usually dissolve in water to form acids.

Differences Between Metals and Non-Metals

              Uses of Non-Metals

1. Oxygen: Used for respiration and combustion.

2. Nitrogen: Used to make ammonia and fertilizers.

3. Carbon (graphite): Used in pencils and as electrode in batteries.

4. Sulphur: Used in making sulphuric acid and matches.

5. Phosphorus: Used in making matches and fertilizers.

6. Chlorine: Used in water purification and making PVC.

7. Hydrogen: Used as fuel and in hydrogenation of oils.