Energy may only be transformed from one sort to another. hope this helps :)
Evolution is defined as change in gene frequency
The rapid transfer of electrons from the ground to the charged clouds, causing a brilliant flash of light.
The degree of polarity of diatomic molecule is related to the difference of electronegativity of the two atoms. If the difference is very large, i.e. one atom is highly electronegative and the other atom is highly electropostive then, the covalent bond is formed. But if the difference between the electronegativities is very less, then its likely that ionic bond is formed.