CBSE Tutorials

Chemistry IX | Matter-Its Nature and Behaviour | Part 1

Matter-Its Nature and Behaviour | Part 1 INTRODUCTION Matter · Anything that occupies space , possesses mass and exert pressure is called matter. Element · An element is a substance which cannot be split up into two or more simpler substances by the any chemical and physical methods of applying heat, light or electric energy.…

August 27, 2015
Biology IX | Health and Diseases | Part 2

Health and Diseases | Part 2 Disease caused by bacteria Tuberculosis (T.B.) Tuberculosis (T.B.) was first discovered by Robert Koch in 1882. It is caused by a bacterium called Mycobacterium tuberculosis. The bacterium releases a toxin called tuberculin. T.B. can affect all parts of the body. In human beings, the infection spreads by inhaling infected…

August 26, 2015

Chemistry IX | Matter-Its Nature and Behaviour | Part 1