Notes and Study material for Exams
Matter In Our Surroundings, Elements, Compounds, Mixtures Matter is any thing which has mass and occupies space. All solids, liquids and gases around us are made of matter. Scientist believe that matter is made of tiny particles that clump together. You cannot see these particles but you can see the matter, for example, a book, … Read more
Molecules Molecule, a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance. The division of a sample of a substance into progressively smaller parts produces no change in either its composition or its chemical properties until parts … Read more
Atomic structure In 1897 J.J. Thomson discovered electron as a constituent of atom. He determined that an electron had a negative charge and had very little mass as compared to that of the atom. Since an atom was found to be electrically neutral it was inferred that some source of positive charge must be present … Read more
The Rate of a Chemical Reaction can be defined as the amount of the reaction which occurs in unit time. The rate of a reaction is measured by choosing certain properties of the reaction which will indicate how far the reaction has gone, and whose magnitude can be observed with time without disturbing the reaction. … Read more
Acid An acid is a substance which forms H+ ions as the only positive ion in aqueous solution. Examples:- Hydrochloric acid dissolved in water forms H+ and Cl– ions HCl —> H+ + Cl– Sulphuric acid dissolved in water forms H+ and SO42- ions H2SO4 —>2H+ + SO42- Nitric acid forms H+ and NO3– ions when dissolved in water HNO3 —> H+ + NO3– … Read more