Answer
a) Chemical
b) Chemical
c) Physical
d) Physical
e) Chemical
Work Step by Step
a) When iron rusts, its chemical composition is completely changed. In fact, it is only because a chemical reaction takes place that the iron is able to change into rust.
b) When water in industrialized places evaporates into the air, its chemical compositions has been altered due to the chemicals and carcinogens in the air around it. As the rain's chemical composition is altered--turning it into acid rain--this is a chemical property.
c) Hemoglobin molecules do not undergo a chemical change that turns them red. This is therefore a physical property of hemoglobin.
d) Evaporation is merely a physical change of water from liquid to gaseous state. However, the chemical composition of the water does not change. As a result, this is a physical change not a chemical one.
e) During photosynthesis, the carbon dioxide is converted to complex molecules through a complex chemical reaction. As the carbon dioxide's genetic makeup is altered, this is a chemical reaction.
