Difference between Metals & Non metals :-
| Metals | Non-Metals |
1. These are the substances which are electropositive in nature i.e., they have a tendency to lose electrons. 2. They generally have 1, 2, or 3 electrons in their outermost shell |
1. These are the substances which are electronegative in nature ie. they have a tendency to gain electrons. 2. They generally have 4 to 8 electrons in their outermost shell. |
Metals :-
Metals are elements which form positive ions by losing electrons during a chemical reaction.eg. aluminum , iron, etc.
Physical properties of Metals :-
1. Malleable - can be beaten into thin sheets. Gold and silver - most malleable. Next- aluminium and copper . Used for making foils, bottle caps, utensils, boxes, buckets, etc.
2. Ductile - can be drawn into thin wires. Gold is most ductile , than silver , copper, aluminium , iron, magnesium, tungsten. Used as electric wires, magnesium wires used in labs, filaments.
3. Good conductors of heat - allow heat to pass through them easily . Silver is best conductor , than copper, aluminium. Lead and mercury are poorest conductors. Used for making utensils and water boilers.
4. Good conductors of electricity - electricity can pass through easily. Silver , copper, gold, aluminium, tungsten. Used for making electric wires.
5. Lustrous and can be polished - have shiny appearance and are good reflectors of light.
Gold, silver, copper.
Used in making jewellery and decoration pieces, mirrors (silver), reflectors.
- Metals lose their shine on keeping in air for a long time and acquire a dull appearance due to formation of a thin layer of oxide , carbonate or sulphide on their surface. If we rub the dull surface with sand paper , outer corroded layer is removed.
6. Hard and strong - almost all are hard and strong. They can hold large weights. Used in construction of bridges, buildings, machines, vehicles, etc.
- Alkali metals (Sodium, potassium and Lithium ) are soft metals which can easily be cut by a knife.
7. Solid at room temp. -
- Only mercury is in liquid state at room temperature.
8. High melting and boiling points - solids melt and turn into liquid on heating at high temperatures.
- Iron, copper have high melting points but sodium and potassium have low melting points. Gallium and cesium have very low melting points, they start melting in hand.
9. High density - are heavy substances.
- Sodium and potassium have low densities and are very light metals.
10. Sonorous - capable of producing a deep or ringing sound. Used for making bells, strings of musical instruments.
11. Usually have silver or grey colour -
- Copper has reddish brown colour and gold has yellow colour.
