(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.
(d) Carbon (Diamond).
(e) Non-metals react with oxygen to form acidic oxides or neutral oxides. Carbon burns in air to form carbon dioxide.
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.