Chemical Bonding . Overview . Bonding and structure explains the properties of a substance! . Physical & Chemical Properties . ‘property’: ‘what something is like’
Bonding and structure explains the properties of a substance!
Solubility in water (or other solvents)
Melting and boiling points
An ionic bond…
is the force of attraction between opppositely charged ions in a compound.
Ionic compounds have high melting and boiling points.
Ionic compounds do not conduct electricity in the solid state. It conducts electricity in the molten and aqueous state.
Why do ionic compounds only conduct electricity in the molten or aqueous state, but not in the solid state?
Ionic compounds are soluble in water but insoluble in organic solvents.
Ionic compounds are not volatile and hence, have no smell.
A volatile substance evaporates easily.
Ionic compounds are hard, crystalline solids.
(PS: Everybody wants to be noble!!)
A covalent bond is…
a bond formed by the sharing of a pair of electrons.
Atoms are held together by strong covalent bonds
Weak intermolecular forces(van der Waals’ forces)
Within each iodine molecule, the iodine atoms are held together by strong covalent bonds.
Between the iodine molecules, there are only weak van der Waals’ forcesholding the molecules together.
In a molecule of methane, CH4, the four C–H covalent bonds are strong.
However, weak intermolecular forces between methane molecules hold them together loosely. Therefore, methane exists as a gas at room temperature and pressure.