The electronic configuration of metal A is 2,8,18,1.
The metal A when exposed to air and moisture forms B a green layered compound. A with con. H₂SO₄ forms C and D along with water. D is a gaseous compound. Find A,B,C and D.

A solution is prepared by dissolving 45 g of sugar in 180 g of water. Calculate the mass percentage of solute.

How does pH play an important role in everyday life?

What is respiratory quotient?

Leeches do not have an elaborate secretion of digestive juices and enzymes -Why?

Why is the Sinoatrial node called the pacemaker of heart?

Differentiate between Medullated and non-medullated nerve fibre.

What are the hormones secreted by posterior lobe of the pituitary gland? Mention the tissues on which they exert their effect.

Why are the human testes located outside the abdominal cavity? Name the pouch in which they are present .

A pure tall plant (TT) is crossed with pure dwarf plant (tt), What would be the F₁ and F₂ generations? Explain.

Define Ethnobotany and write its importance.

How are stem cells useful in regenerative process?

Name any three foods that are to be avoided and included in the diet of a diabetic patient. Why should it be followed?

What are the advantages of using biogas?

Program for print the word “Hello” with sound