For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
If iron is having an oxidation state of +3 called as cation. Sulphur is an anion with oxidation state of -2 and forms sulphide ion . Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral .
The cations and anions being oppositely charged attract each other through strong coloumbic forces and form an ionic bond.
A chemical change is a change in the chemical makeup of a substance and results in a new substance. Ice and water both have the same chemical makeup - ice is just a different state and has the same atoms but in an expanded form.
In the diagram Carbon and each of the 4 Hydrogens are sharing electrons. They are also both non metals. Both of these are characteristics of Covalent Bonds.
When a material is heated, the kinetic energy of that material increases and its atoms and molecules move about more. This means that each atom will take up more space due to its movement so the material will expand. ... Some metals expand more than others due to differences in the forces between the atoms / molecules.
