Questions

Tropical grasslands, or savannas, are also the homes of primates in Africa and Asia; no savanna-living primates exist in South America. Tropical grasslands comprise a mixture of trees and grasses, the proportion of trees to grass varying directly with the rainfall.

A Libraury. It has more number of story books in it to read.

When atoms react they do so in order to reach the lowest energy, which is the most stable. The electrons orbitals will overlap in the way that reduces the energy the most. Orbitals of similar energy will produce the greatest stabilisation.The answer you gave isn't the whole story, it depends what species is reacting with what. The effective nuclear charge on the atom will affect the energy of the valance electrons.

Hence, the reactivity of an atom arises from the existence of unpaired electrons in the valence shell.

An owl.

"What noise does an owl make?

The sound an Owl makes, it sounds like, "Who?" to our ears.

They sounds entire lives asking the same question, but they'll never give any answers.