Matter. Chapter 2. Section 1: What is Matter? Objectives. Explain the relationship between matter, atoms, and elements. Distinguish between elements and compounds. Describe molecules, and explain how they are formed. Interpret and write some common chemical formulas.
Matter <- molecules <- compounds <- elements <- atoms
C16 H10 N2 O2
16 carbon atoms
10 hydrogen atoms
2 oxygen atoms
2 nitrogen atoms
A piece of tin has a mass of 16.52 g and a volume of 2.26 cm3. What is the density of tin?
Chemical changes can be detected by looking for certain clues. A change in odor or color is a good clue. When food burns, you can often smell the gases given off. When bubbles form, that’s usually a good clue as well. Fizzing, foaming, or the production of sound, heat, light, or odor are all good clues.
Because new substance are formed during a chemical change, you cannot reverse the process using physical changes.