Metals, Non-metals and Metalloids

(A) Metals

These are good conductor of electricity (max. in silver) and heat, generally in solid form at room temperature (Exception: Mercury, which exist in liquid form at room temperature) have luster Ex. Copper, silver, gold etc.

Physical Properties of Metal

·         lustrous (shiny)

·         good conductors of heat and electricity

·         high melting point

·         high density (heavy for their size)

·         malleable (can be hammered)

·         ductile (can be drawn into wires)

·         usually solid at room temperature (an exception is mercury)

·         opaque as a thin sheet (can't see through metals)

·         metals are sonorous or make a bell-like sound when struck

Metallurgy

The process of extraction of a metal in a pure state on a large scale from its one by physical or chemical means is called metallurgy.

Ores 

Those minerals from which the metals are extracted commercially and economically and with minimum effort are called ores of the metal.

All ores of the metals are minerals but all minerals are not ones.

Gangue 

The earthy and other insoluble impurities associated with the minerals are known as gangue.

Some important facts

·         Polonium has the maximum number of isotopes.
.     Diamond has maximum refractive index and due to total internal reflection.

·         Radon is the heaviest gas.

·         Silver is the best conductor of electricity.

·         To avoid melting of ice gelatine is used.

·         When dry ice is heated it is directly converted into gas.

·         Acetyline is used for light production.

·         Cardium rod is used in nuclear reactor to slow down the speed of neutron.

·         In tube light there is the vapour of mercury and argon.

·         Zeolite is used to remove hardness of water.

·         Silver iodide is used in artificial rain.

·         Nichrome wire is used in electrical heater.

·         Iron phritey is known as fools gold.

WATER

·         It is colourless, odourless and tasteless liquid.Of the total global water, the oceans and inland saline water bodies hold 97.3% and the fresh water amounts to only 2.7%.Water constitute about 65% of our body and is an essential element for its growth.

·         The density of ice is less than that of water and hence ice floats over water.

·         Water has maximum density (1 g) at 4°C.

·         M.P. is 273.2 K and B.P. is 373.2 K.

Heavy Water

Chemically heavy water is deuterium oxide (D20). It was discovered by Urey in 1932. It has been finding use in nuclear reactors as a moderator because it slows the fast moving neutrons.

Properties of water

The freezing point, boiling point, heat of fusion and heat of vaporisation of water are higher as compared to the hydrides of the other members of same group of oxygen.

(B)Non-METALS

They have the property opposite to the metals. They are found in solid, liquid and gaseous form. Ex. Carbon, oxygen etc. There are 24 non-metals. Gases – 11, Solid-12, Liquid-1

Si and Ge is semi conductor (Generally these are bad conductor of electricity and heat)

Nonmetal Physical Properties

·         not lustrous (dull appearance)

·         poor conductors of heat and electricity

·         non ductile solids

·         brittle solids

·         may be solids, liquids or gases at room temperature

·         transparent as a thin sheet

Some important Non Metal

(i)Hydrogen

It is the lightest gas. It has three isotopes

Protium – 1H^1, Denterium – 1H^2, Tritium – 1H³

(ii)Nitrogen

78% by volume in atmosphere. Liquid nitrogen is used for refrigeration

Ammonia is the compound of nitrogen which is prepared by Haber’s process.

(iii)Phosphorus

An important constituent of animal and plants. It is present in bones and DNA.

(C)Metallolids

Those elements which pass both metallic and non-metallic properties are known as metalloid. Ex. Antimony, Silicon, Boron, Arsenic etc.