covalent bonding

Question 1

covalent bonding

Answer 1

when non-metal atoms share pairs of electrons together to get a full outer shell.

Question 2

why they are so strong:

Answer 2

the positively charged nuclei of the bonded atoms are attracted to the shared pair of electrons by electrostatic forces.

Question 3

dot and cross diagrams:

Answer 3

• shows which atoms the electrons come from.
• don’t show relative sizes of atoms.
• don’t show how the atoms are arranged in space.

Question 4

displayed formula:

Answer 4

• shows how atoms are connected.
• doesn’t show 3D structure of the molecule.
• doesn’t show which atom the electrons come from.

Question 5

3D model:

Answer 5

• hard to predict what shape the molecule will make.

Question 6

types of substances covalent bonds can make:

Answer 6

• simple molecular substances: small molecules in which the atoms are joined together by strong covalent bonds, but between the bonds = weak intermolecular forces. (e.g. CH4 + H2O)
• polymers: long chains made out of monomers
• giant covalent structures: millions of atoms arranged in a regular lattice structure - really strong due to covalent bonds.

Question 7

simple molecule:

Answer 7

a simple molecule has multiple atoms covalently bonded together. these covalent bonds between atoms are very strong.

forces of attraction between separate molecules are weak so molecules can easily be separated.