FREE NCERT MATERIAL
Acids, Bases and Salts
The sour and bitter tastes of food are due to acids and bases present in them. Acids are sour in taste and change the color
ANIMAL TISSUES
The contraction and relaxation of these cells result in movement. Blood flows and carries various substances from one part of the body to the other.
ATOMS AND MOLECULES
Around 500 B.C., Indian philosopher Maharishi Kanad, postulated the theory if we go on dividing matter (padarth), we will obtain the smallest particle beyond which
Carbon and its Compounds
Compounds are of two types:(i) Organic Compounds(ii) Inorganic Compounds Organic Compounds are made up of Carbons and form the basis of all living organisms. THE
CELL — STRUCTURE AND FUNCTIONS
All organisms are made of smaller parts called organs. Organs are made of still smaller parts. The smallest living part of an organism is a
CHEMICAL BONDING AND MOLECULAR STRUCTURE
CHEMICAL BOND The force that holds different atoms in a molecule is called a chemical bond. OCTET RULE Atoms of different elements take part in
CHEMICAL EFFECTS OF ELECTRIC CURRENT
Materials, which allow electric current to pass through them, are good conductors of electricity. Materials, which do not allow electric current to pass through them easily,
Chemical Reactions and Equations
Most of the substance around us undergoes various changes. Some of these changes are temporary with no new substance being formed. They are called physical
CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
GENESIS OF PERIODIC CLASSIFICATION DOBEREINER’S TRIADS In 1829, Dobereiner arranged certain elements with similar properties in groups of three in such a way that the
Coal and Petroleum
Natural Resources Resources include everything provided by the nature. They form the wealth of a country. Types of Natural Resources: (i) Inexhaustible: There are some
COMBUSTION AND FLAME
Combustion is a chemical process in which a substance reacts with oxygen to give off heat. The substance that undergoes combustion is said to be
CONSERVATION OF PLANTS AND ANIMALS
Deforestation and Its Consequences Deforestation: clearing of forests and using that land for other purposes. Consequences: Deforestation increases the temperature and pollution level on the
Control and Coordination
All the living organisms respond and react to changes in the environment around them. The changes in the environment to which the organisms respond and
CROP PRODUCTION AND MANAGEMENT
Introduction All living organisms require food. Plants can make their food themselves whereas animals including humans can not make their own food. Humans get their