Learner's Area

There are nine species of vultures in India It is believed that the population of three species of vultures has declined by about 95% since 1990s in Indian sub continent. India is witnessing this vulture crisis, largely  due to the following reasons : * Food scarcity caused by changes in disposal practice of dead cattle in developed areas and cities.  Having couple  competition with other scavenger such as start dogs etc whose population have  increased. * Decline  in the number of tall trees preferred for nesting and roosting. * Anthropogenic pressure, industrialization, urbanization etc., Various measures indicated for conversation of vultures in India include awareness rising among people, policymakers, veterinarians other stake holders establishment of vulture Breeding centers and initiation of population monitoring of vulture.

Most of the frog legs served as delicacies in Europe comes from Asian bullfrogs. The majority of these frog legs are imported from India, Malaysia, Bangladesh and Indonesia has recently join this list. The export  of frog legs from  India started in early sixties. As a result of excessive exploitation, the population of bull frog  has fallen  dramatically . Their extinction can gave lot of impact on the environment. Frogs play a vital role in eradicating insects pests in rice  fields. The decline in frog has resulted in an increase in use of pesticides.  Bull frogs are know to eat mice,small turtles, fish, snakes, birds and other frogs. However bulk of their diet Is insects, spider,crayfish and other invertebrates. Reduction in frog population can cause increase in spread of malaria,encephalitis and other diseases which are carried by insects.  So taking frogs from the wild life could have devastating consequences.

Biodiversity,  the variety of life on earth is quite possibly the most amazing thing on the planet. It is key to sustaining health, wealth, food fuel and all vital services we depend on . Its magnificene enriches our culture and regional traditions. It consists of all the species of animals and plants and other life forms and the variety that exists within each species.  It's  also include the range of ecosystem such as deserts,oceans and tropical rainforest. Biodiversity can be small big bold  and beautiful. All the living things and their neighbors in the sea on the land and in the air are part of the biodiversity.  Without  biodiversity,  humans could not  exist.

Transition elements are metals.They are less reactive than metals of s block The characteristics are 1)They exhibit variable valence Reason : The core of the metal atom is stable. So it may lose one are more electrons and thus variable valence. 2) Their ion are coloured Reason: presence of unfilled d orbital 3) They're from complexes Reason : the d orbital involve in co-ordinate bond formation. 4) They give interstitial compounds Reason : Non metal atoms enter into interstitial spaces of the metal particles 5)the metals or their oxides are used as catalyst Reason : Free valencies are left over on finely divided metal properties.

When  X rays are produced? X rays  are produced effectively when electron strike the dense metal anode, which is called target. As come for the properties of X-ray 1)They don't deflected by electric and magnetic 2)They have high penetrating power through the matter due to this reason these rays are used to study the interior  of the objects

Comment the chemical formulas of following Sodium sulphate Barium chloride Propane Magnesium oxide Quick lime Lead nitrate Sliver bromide Sodium hyrogen carbonate Sodium carbonate Sodium zincate Acetic acid Acetone Potassium sulphate Sodium sulphate baking soda Bleaching powder Washing soda Plaster of Paris

Important questions in last topic Definition  of heat? Definition of temperature? What is absolute temperature? Units of Heat?