What is an Element?

Elements: An element is defined as the pure substance which is made of only one kind of particles. These particles may be atoms or molecules.

• Carbon sulphur, iron, lead, gold, mercury, hydrogen, oxygen, and nitrogen are some examples of familiar elements.
• Iron, gold, copper etc contain single atoms as constituent particles held together.
• Hydrogen, oxygen, nitrogen etc consists of molecules, comprising of two atoms combined together.
• The no of elements known to-date is 114. Out of these elements known, 92 are occurs in earth’s crust and the left one have been prepared artificially in the laboratory through nuclear reactions.

Types of elements:

Elements are classified as:

Metals: Metals are those elements which possess lustre (shining appearance), reflects light, are good conductors of heat and electricity, are malleable (hammered to thin sheets) and ductile (drawn into wires), exist as solid at room temperature (except mercury), possess high density.

• Example: iron, copper, silver, gold etc.

Non-metals: Non-metals are those elements which does not reflects light, poor conductors of heat and electricity (except graphite), does not possess malleability and ductility, do not have lustre (except iodine), exists in all the three states.

• Example: carbon, hydrogen, oxygen, nitrogen etc.

Metalloids: Metalloids are those elements which exhibits the property of both metals and non-metals.

• Example: Arsenic, antimony and bismuth.