Introduction of Pure substances
A Pure substance is which contains a single type of constituent particles. For example gold, water etc.
so Based on the nature of the particles it is classified into two types which are elements and compounds.
Elements
In the lesson pure substance This term was first used by a person named Robert Boyle in 1661.
According to Antoine Laurent Lavoisier, a French chemist, 1743 to 1794.
Till now 118 elements be discovered, out of these 92 are natural elements and are man-made.
On the basis of variation in properties
Elements can be broadly classified as metals, non-metals and metalloids.
Metals in Pure Substances
metal is an element that is malleable ductile and conduct heat and electricity they are lustrous.
They have silvery-grey or golden yellow colour.
Mercury is the only metal that is at the liquid at room temperature.
Non Metals
An element that is neither malleable nor ductile.
It conducts heat and electricity they will display a variety of colours.
Example hydrogen Oxygen and carbon bromine chlorine.
Bromine is the only non-metallic element that exists in a liquid state at the normal condition of temperature and pressure.
Metalloids
So intermediate properties in those of metals and nonmetals is metalloids.
Example: boron,silicon,germanium etc.
Compounds
So A compound is made up of two or more elements that are chemically bonded to each other in a constant ratio.
Example: Water, methane, carbon dioxide, ammonia