CHAPTER 2 MATERIALS: METALS AND NON-METALS
PHYSICAL PROPERTIES OF METALS
- Hard
- Lustrous
- Malleable (can be beaten into sheets)
- Ductile (can be drawn into wires)
- Sonorous (produce a ringing sound when struck)
- Good conductors of heat and electricity)
PHYSICAL PROPERTIES OF NON-METALS
- Soft
- Dull in appearance
- Not malleable, instead breaks down into a powdery mass when beaten with a hammer)
- Not sonorous
- Poor conductors of heat and electricity
CHEMICAL PROPERTIES OF METALS ANDS NON-METALS
- Reaction with oxygen: Metals react with oxygen to form their oxides. These oxides are basic in nature. Non-metals react with oxygen to produce non-metallic oxides. These oxides are acidic in nature.
- Reaction with acids: Metals react with acids to produce their salts and give out hydrogen gas in the process. Non-metals react do not react with acids.
- Reaction with bases: Some metals react with bases to give out hydrogen gas. The reaction of non-metals with base is complex.
- Displacement reaction: When a more reactive metal displaces the less reactive metal from its aqueous solution, it is called displacement reaction.
USE OF METALS
- In making machines and automobiles.
- In making gadgets
- In making utensils
- In making various daily use articles
USE OF NON-METALS
- Used in fertilizers
- Essential for living beings as we breathe in oxygen which is a non-metal.
- Used in water purification process