C2.13 Properties Of Covalent Substances

Question 1

What are the properties of giant molecular covalent substances?

Answer 1

They have high boiling and melting points because of strong covalent bonds, you need a lot of heat energy to break these bonds.

Question 2

What are the differences between graphite and diamond?

Answer 2

Graphite has layers which rub easily and although covalent bonds within layers are very strong, there are weak forces between the layers. Good conductors of electricity, one electron fro each carbon atom that can move along layers.

Diamonds are very hard because all the atoms are joined with strong covalent bonds. Doesn’t conduct electricity no free electrons or charged particles to move around

Question 3

Why can graphite be used for lubricants and electrodes?

Answer 3

Lubricants - they have layers which rub easily and although covalent bonds in the layers are strong, only weak forces between layers. Very soft.

Electrodes - good conductor of electricity. Free electrons which move along layers

Question 4

Why can diamond be used as a cutting tool?

Answer 4

Atoms are joined with strong covalent bonds

Question 5

What are the properties of simple molecular covalent substances?

Answer 5

Substances which have low melting and boiling points because there are only weak forces between neighbouring molecules. Poor conductors of electricity because they don’t have charged particles