Answer: Fundamental, Key, vital, crucial
Explanation:
The solvent is usually referred to as the component of a solution which is present as the one with the larger quantity and in most cases as the liquid which dissolves a solid. In a solution, there are two components namely the solvent and the solute. The solute is the one in smaller amount.
Sharing of two electrons make a <u>Covalent </u>bond.
<u>Explanation: </u>
Attractions among the atoms bring them together. So the electrons from each of the atoms are attracted towards the nucleus of those two atoms, that “share” the electrons produces a covalent bond.
It is also named as molecular bond, a bond that entails the sharing of a pair of electrons among the atoms. When the atoms share the electrons among themselves, it produces a molecule, which is more stable than the atom.
If the attractions between the atoms are strong enough and if every atom has enough space for the electrons in its outermost energy level then there occurs covalent bonding. So electrons are very important in the covalent bond formation.
Option C: elements produce spectra with only few distinct lines.
The spectra are not continuos and are different for every element. This permits to identify elements.