1a. A
is formed by two atoms
one or more pairs of electrons to make a
between the two atoms in a molecule.
1b. However, between small molecules, only a
holds them together in the bulk liquid or solid.
1c. This results in small covalent molecules having
and
if solid.
1d. Small covalent molecules have no
and so have a
.
2a. The Group 7
collectively known as the
form diatomic molecules of two atoms.
2b. The
between the molecules are
giving them relatively low melting points and boiling points.
2c. This also explains why they are gases, liquids or solids with
.
2d. As you go down Group 7 the melting boiling points and boiling points
because the molecules get
and the intermolecular forces
.
3a. In giant covalent structures the forces between all the atoms are
forming
like
or silica
.
3b. In the atomic giant structure metals there are free electrons which allow
.