By discussing the structure and bonding properties of chlorine and sodium chloride, explain why chlorine is a gas at room temperature but sodium chloride is a solid.

Chlorine is a gas at room temperature because it is composed of diatomic molecules, Cl2. The two chlorine atoms are held together by a covalent bond, which is a type of chemical bond where two atoms share electrons in order to achieve a more stable electron configuration. Because chlorine has a relatively low atomic number (17), the electrons in the bond are not strongly attracted to the positively charged nucleus and are therefore relatively easily shared between the two atoms. This results in a weak intermolecular force between chlorine molecules, which allows them to move freely and remain in a gaseous state at room temperature and pressure.

On the other hand, sodium chloride is a solid at room temperature because it is an ionic compound composed of sodium cations (Na+) and chloride anions (Cl-) held together by ionic bonds. An ionic bond is a type of chemical bond that involves the transfer of electrons from one atom to another, resulting in the formation of oppositely charged ions that are attracted to each other due to their opposite charges. In the case of sodium chloride, the positively charged sodium ions are attracted to the negatively charged chloride ions, forming a crystalline lattice structure.