The Lewis structure indicates that each Cl atom has three pairs of electrons that are not used in bonding (called lone pairs) and one shared pair of electrons (written between the atoms). A dash (or line) is sometimes used to indicate a shared pair of electrons: A single shared pair of electrons is called a single bond.
The lights shown in the figure comes from the outermost layer of the Sun. This layer is called photosphere. This is the layer from where the light of the Sun is radiated, before travelling through space and reaching us.
