Answer
a. Chemistry is a science that studies the properties, structures, reactions and composition of the substances in our world.
b. A chemical is a substance that is used in or made by a chemical process. Its main characteristic is that it always has the same properties and composition, no matter where it is found.
Work Step by Step
a. You can find the answer to this question in the first sentence of the topic '1.1 Chemistry and Chemicals'. (Page 2)
b. You can find the answer to this question in the first sentence of the 'Chemicals ' section. (Page 3)
