H2 is a gas which forms when two hydrogen atoms bond together and become a hydrogen molecule. H2 is also called molecular hydrogen.It consists of two protons and two electrons. Consequently it is the most common form of Hydrogen because it is stable with a neutral charge. ... H2 is the smallest molecule in the universe.
Answer:A
Explanation:The anatomy and behavior of that animal's immediate ancestor..
Several species of warblers can live in the same spruce tree only because they occupy different nitches within the tree. So option "c" is the correct option as far as the given question is concerned. These birds may not be of the same species but they do have some similarities like they are very vocal and can be rarely seen but definitely heard. All species of warblers are insectivorous and also very small. As they are small so identifying them can be very difficult for a person. These birds are mostly dull greenish or brownish in color.