ICSE Class 9 Answered

Radical

• Radical is an atom or a group of atoms of same or different elements which behaves like a single atom with a positive or a negative charge on it. 
• Radicals have their own combining power based on which they form chemical formulae. 
• Example: NH₄⁺, Na⁺, NO₃⁻, SO₄²⁻ 

Compounds:

• When two or more different elements are combined chemically in a fixed proportion, a compound is formed.
• Being a pure substance A compound has definite set of properties.
• Elements in a compound cannot be separated by physical method.
• In the chemical compound, the elements are always present in a definite proportion.
• Example: Water (H₂O)