Classify each of the following as a compound or a mixture. If it is
impossible to tell, explain why.
a. a solid combination of iron and oxygen, no part of which is
attracted to a magnet
b. a material containing 88.8% oxygen and 11.2% hydrogen
c. a material that is explosive and that contains 88.8% oxygen and
11.2% hydrogen
d. a material that consists of blue particles and red particles
e. a material containing only hydrogen and oxygen that is a gas
under ordinary room conditions