Substance categories

Question 1

Name some covalent network substances & their properties (eg. melting points, electrical conductivity)…

Answer 1

Carbon (C) as diamond
Silicon (Si)
- very high melting points
- electrical conductivity: nil

Question 2

Name some ionic substances & their properties (eg. melting points, electrical conductivity)…

Answer 2

Sodium chloride (NaCl)
magnesium fluoride (MgF2)
- high melting points
- electrical conductivity: solid, nil; molten, high

Question 3

Name some metallic substances & their properties (eg. melting points, electrical conductivity)…

Answer 3

copper (Cu)
gold (Au)
silver (Ag)
sodium (Na)
- mostly high melting points but can be variable
- electrical conductivity: high both states

Question 4

Name some molecular substances & their properties (eg. melting points, electrical conductivity)…

Answer 4

oxygen (O2)
water (H2O)
methane (CH4)
cocaine (C17H21NO4)
- low melting points
- electrical conductivity: nil