UP Board Class 12 th Chemistry paper 1 is scheduled to be held on February 20, 2018, and Paper 2 will be held on February 22, 2018. Students find chemistry a difficult subject because of the chemical ...

1 Write a word equation for the reaction. 2 Write a simple equation by writing the name of each substance with its symbol or formula. 3 Check whether the equation is balanced by counting the atoms of ...

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 ...

Chemical reactions make new chemicals. Atoms are rearranged during a chemical reaction, but the number of atoms does not change. A catalyst is a substance that speeds up a chemical reaction. Catalysts ...