Chemistry - Metals and Non-Metals 2

Introduction

• A solid material, which is typically hard, malleable, shiny, fusible, and ductile, is known as metals. E.g. iron, copper, aluminum, magnesium, sodium, lead, zinc, etc.

• Normally, metals have good electrical and thermal conductivity.

• Metals, in their pure state, have a shining surface, known as metallic luster.

• Metals can be beaten into thin sheets; this property is known as malleability.

• The property of metals to be drawn into the thin wires is known as ductility. E.g. gold is the most ductile metal.

• Silver and copper are the best heat conductor.

Non-Metals

• The non-metals are normally found in either solids or gases states. However, bromine is an exception that found in liquid state.

• Some of the major examples of non-metals are carbon, sulphur, iodine, oxygen, hydrogen, etc.

Facts of Metals and Non-metals

• All metals exist in the solid form at room temperature, except mercury.

• Gallium and caesium have very low melting points; these two metals get melt even on palm.

• Iodine is a non-metal, but it is lustrous (lustrous is the property of metal).

• Carbon is a non-metal that can exist in different forms. Each form is called an allotrope.

• Diamond is an allotrope of carbon and it is the hardest natural substance known.

• The melting and boiling point of diamond is very high.

• Graphite is also allotrope of carbon; it is a conductor of electricity.

• Alkali metals, such as lithium, potassium, sodium, are the examples of soft metals, as they can be cut with a knife.

• Nearly all metals when combined with oxygen, it forms metal oxides.

• Different metals have different frequency of reaction; some react slow, but some react very fast. E.g. potassium and sodium are very reactive and they catch fire only if kept in the open.

• Therefore, potassium and sodium are kept immersed in kerosene oil so that they cannot catch fire.

• However, among all metals, sodium (most likely), is the most reactive metal.

• Anodizing is a process of forming a thick protective oxide layer of aluminum and it protects from corrosion.

• The elements or compounds that occur naturally in the crust (upper layer) of the earth, are known as minerals.

• The minerals in raw form is known as ores. E.g. gold, silver, iron etc. (iron ore shown in the image given below) −

• The ores, which are extracted from the earth, are usually contaminated with large amounts of impurities such as mix with some elements, soil, sand, etc., known as ‘gangue’.

• Based on the reactive nature and extraction from the ores, metals can be categorized as −