Write the number of vertical columns in the modern periodic table. What are these columns called?

Give the respective scientific terms used for studying:

(i) the mechanism by which variations are created and inherited and

(ii) the development of new type of organisms from the existing ones.

Water is a valuable resource. List two ways that you would suggest every family member to save this resource.

List four advantages of vegetative propagation.

Draw a ray diagram to show the path of the reflected ray corresponding to an incident ray which is directed towards the principal focus of a convex mirror.Mark on it the angle of incidence and the angle of reflection.