Year 9 Chemistry – Worksheet 9
2.2 Ionic compounds
1. Complete the following sentences:
Atoms whose highest energy level is full are chemically __________. The elements with full highest energy levels, for example _______, are called _________ ________.
Atoms of other elements do not have full outer orbitals and are more ___________.
These atoms try to gain or lose electrons by forming bonds to have full outer shells.
Bonding only involves the electrons in the outer orbitals – the valence electrons.
Because for most elements, exceptions are for example _____________ and
_____________, a full highest energy level consists of _________ electrons the rule that all atoms try to achieve a full valence shell is called the octet rule.
There are three main types of bonding:
a. ___________ bonding occurs between metal and non-metal atoms b. ___________ bonding occurs between non-metal and non-metal atoms c. ___________ bonding occurs between metal and metal atoms
Ion formation
One way of forming ions is for atoms to gain or lose electrons.
Positive ions (or cations) are formed when an atom loses one or more electrons. Metal atoms usually form cations.
Negative ions (or anions) are formed when an atom gains one or more electrons. Non-metal atoms usually form anions.
2. Predict the ions for the following elements
Element Electron
configuration
Valence electrons Ion
Oxygen O 2,6 6
It will gain 2 electrons to complete the outer orbital
O2-
Magnesium Mg
Fluorine F
Lithium Li
Chlorine Cl
Sodium Na
Year 9 Chemistry – Worksheet 9
3. Using our orbital formation method, draw electron configuration diagrams for the following atoms and the ions;
Cl
Cl
-2,8,7 [2,8,8] -
Mg
O
2-
