The processes like crystallisation, boiling, vaporisation, burning of colour, melting point, hardness etc, are called physical changes. These are reversible in nature. The processes like ...

The Schrödinger equation rewrote the rules of matter and forever changed the field of chemistry. Donald Truhlar, a chemist at the University of Minnesota, calls it the “greatest advance of the 20th ...

“THE inability to balance a chemical equation is a most common difficulty to students of chemistry.” The author has attempted to remedy this very common weakness, and in addition to a concise ...

when two or more substances (elements or compounds) combine to form a single product, the reactions are called combination reaction.

The speed of a chemical reaction is affected by temperature, concentration, particle size and the presence of a catalyst. It can be calculated by measuring changes in reactants/products. Revise: ...

An acid and alkali will neutralise each other and produce a salt and water. This is called a neutralisation reaction. The name of the salt produced can be worked out from the names of the acid and the ...

Section A covers Biology, with 16 questions carrying 30 marks. Section B covers Chemistry, with 13 questions carrying 25 marks.