1. Chemistry is the study of
matter and its changes.
2. All the matter is composed of fundamental units called atoms.
3. The science of chemistry is important for improving the standards of living.
4. The nucleus of the atom is composed of two particles called protons and
neutrons.
5. Chemistry provides employment for a large variety of people.
6. The simplification of chemical problems is made by classifying matter.
7. The behavior of the four forms of matter can be explained by the fact that
all matter consists of particles in motion.
8. The universe is made of more than 90 elements.
9. Chemistry involves __ the study of chemical elements and how they combine.