(a) Define non-metals. Give five examples of non-metals.
(b) Name a non-metal which conducts electricity.
(c) Name a non-metal having lustre (shining surface).
(d) Name a non-metal which is extremely hard.
(e) How do non-metals react with oxygen? Explain with an example. Give equation of the reaction involved. What is the nature of the product formed? How will you demonstrate it?
(a) Non-metals are the elements that do not conduct heat and electricity and are neither malleable nor ductile.
Example: Carbon, sulphur, phosphorus, silicon and oxygen.
(b) Carbon.
(c) Iodine.
(d) Carbon (Diamond).
(e) Non-metals react with oxygen to form acidic oxides or neutral oxides. Carbon burns in air to form carbon dioxide.
C(s) + O2(g) → CO2(g)
The nature of the product formed is acidic. When carbon dioxide dissolves in water, it forms carbonic acid. It turns blue litmus to red which shows it is acidic in nature.