Objectives of the passage:
1. To explain the basic definition of chemistry and its focus on matter and chemical reactions.
2. To introduce key concepts such as atoms, molecules, and chemical bonds.
3. To highlight the importance of the periodic table in organizing elements.
4. To discuss fundamental chemical principles like pH, states of matter, and energy changes.
5. To provide an understanding of how these concepts are essential for studying the behavior of substances in different conditions.