METAL AND NON-METAL

METALS

On the basis of their physical properties metals are substances which are lustrous, ductile and malleable. They are also good conductors of heat and electricity.

NON-METAL

On the basis of its physical properties non-metal are substances which are brittle, non-lustrous and bad conductor of both heat and electricity.

WE CANNOT GROUP ELEMENTS ACCORDING TO THEIR PHYSICAL PROPERTIES ALONE AS THERE ARE MANY EXCEPTION

-All metals except mercury exist as solid at room temperature.

-Generally metals have high melting points but gallium and caesium have very low melting point.

-Iodine is a non-metal but it is lustrous.

-Carbon is a non-metal that can exist in different forms.Each form is called an allotrope. Diamond an allotrope of carbon is the hardest largest substance known. Graphite another allotrope of carbon is a good conductor of electricity.

-Generally metals are hard but alkali metals are so soft that they can be cut with a knife.

 [ The alkali metals are six chemical elements in the leftmost column in the periodic table. They are lithium, sodium, potassium, rubidium, cesium and francium.]

CHEMICAL PROPERTIES OF METALS AND NON-METALS

REACTION WITH OXYGEN

(A) Metals react with oxygen to form metal oxide.

(B) Non-metal also react with oxygen to form acidic and neutral oxide.

REACTION WITH WATER

(A) Metal react with water to form metal oxide and hydrogen gas. And if metal oxide formed is soluble in water it further reacts with water to form metal hydroxide.

(B) Non-metals do not react with water.

REACTION WITH ACID

(A) Metals react with acid to form salt and hydrogen gas.

(B) Non-metals do not react with dilute acids and don’t displace hydrogen from dilute acids, because non-metals are electron acceptor. So, they cannot supply electrons to H+ ions. So, they do not displace hydrogen from dilute acids.

REACTION OF METAL WITH SOLUTIONS OF OTHER METAL SALTS

Higher reactive metal can displace less reactive metal. It is simple and easy if metal A displaces metal B from its solution, it is more reactive than B.M

THE REACTIVITY SERIES

The reactivity series is a list of metals arranged in the order of their decreasing activities.

IONIC COMPOUND

An ionic compound is a chemical compound composed of ions held together by a strong electrostatic force. The compound is neutral overall, but consists of positive and negative charged particles.