(ii) The diagrams show how the electrons are arranged in the outer shell (highest occupied
energy level) of a phosphorus atom and a chlorine atom.
P
CI
Draw a diagram to show the bonding in a molecule of phosphorus trichloride.
Use dots and crosses to represent the electrons. Show only the outer shell electrons.
.
Answers
II-eight electrons
One sodium (Na) atom gives it's electron to one chlorine (Cl) atom. Chlorine then has the eight electrons in its outer shell attached to the electronic structures of noble gases like neon or argon which have eight electrons in their outer energy levels (or two in the case of helium). These noble gas structures are thought of as being in some way a "desirable" thing for an atom to have. You may well have been left with the strong impression that when other atoms react, they try to achieve noble gas structures. As well as achieving noble gas structures by transferring electrons from one atom to another as in ionic bonding, it is also possible for atoms to reach these stable structures by sharing electrons to give covalent bonds. make it "happy".