TYPES OF PURE SUBSTANCES
On the basis of their chemical composition, substances can be classified either as elements or compounds.
`color{green}("π ππππππππ :")` Pure substances that are made up of only one kind of atoms are known as elements.
Elements can be further divided into metals,non-metals and metalloids.
`color{green}("ππππππππππ ππ ππππππ:")`
`color{green}(β’)` They have a lustre (shine).
`color{green}(β’)` They have silvery-grey or golden-yellow colour.
`color{green}(β’)` They conduct heat and electricity.
`color{green}(β’)` They are ductile (can be drawn into wires).
`color{green}(β’)` They are malleable (can be hammered into thin sheets).
`color{green}(β’)` They are sonorous (make a ringing sound when hit).
Examples of metals are gold, silver, copper, iron, sodium, potassium etc. Mercury is the only metal that is liquid at room temperature.
`color{green}("ππππππππππ ππ πππ-ππππππ:")`
`color{green}(β’)`They display a variety of colours.
`color{green}(β’)` They are poor conductors of heat and electricity.
`color{green}(β’)` They are not lustrous, sonorous or malleable.
Examples of non-metals are hydrogen, oxygen, iodine, carbon (coal, coke), bromine, chlorine etc.
Some elements have intermediate properties between those of metals and non-metals, they are called metalloids; examples are boron, silicon, germanium etc.
`color{green}("π πππππππππ")`
A compound is a substance composed of two or more elements, chemically combined with one another in a fixed proportion.
`color{green}("π ππππππππ :")` Pure substances that are made up of only one kind of atoms are known as elements.
Elements can be further divided into metals,non-metals and metalloids.
`color{green}("ππππππππππ ππ ππππππ:")`
`color{green}(β’)` They have a lustre (shine).
`color{green}(β’)` They have silvery-grey or golden-yellow colour.
`color{green}(β’)` They conduct heat and electricity.
`color{green}(β’)` They are ductile (can be drawn into wires).
`color{green}(β’)` They are malleable (can be hammered into thin sheets).
`color{green}(β’)` They are sonorous (make a ringing sound when hit).
Examples of metals are gold, silver, copper, iron, sodium, potassium etc. Mercury is the only metal that is liquid at room temperature.
`color{green}("ππππππππππ ππ πππ-ππππππ:")`
`color{green}(β’)`They display a variety of colours.
`color{green}(β’)` They are poor conductors of heat and electricity.
`color{green}(β’)` They are not lustrous, sonorous or malleable.
Examples of non-metals are hydrogen, oxygen, iodine, carbon (coal, coke), bromine, chlorine etc.
Some elements have intermediate properties between those of metals and non-metals, they are called metalloids; examples are boron, silicon, germanium etc.
`color{green}("π πππππππππ")`
A compound is a substance composed of two or more elements, chemically combined with one another in a fixed proportion.