Chapter 2 Properties of Matter
Chapter 3 States of Matter
Chapter 4 Atomic Structure
Chapter 5 The Periodic Table
Chapter 6 Chemical Bonds
Chapter 7 Chemical Reactions
Chapter 8 Solutions, Acids, and Bases
Chapter 9 Carbon Chemistry
Chapter 10 Nuclear Chemistry
Focus on the BIG Ideas
Chemistry is the study of the composition, structure, properties, and reactions of matter. Matter that always has exactly the same composition is classified as a substance. Elements are the simplest substances. The smallest particle of an element is an atom.
There are only about 100 elements. In the modern periodic table, elements are arranged by increasing atomic number (number of protons). Based on their chemical and physical properties, elements are classified as metals, nonmetals, and metalloids.
Unlike physical changes, chemical changes involve a change in the composition of matter. During a reaction, chemical bonds in the reactants are broken and chemical bonds in the products are formed. Mass is conserved in chemical reactions.
Nuclear changes (such as radioactivity) involve the conversion of atoms of one element to atoms of another. During nuclear reactions, mass can be created or destroyed, and it is the total sum of mass and energy that is conserved.
Fireworks Display in ▸ Sydney, Australia When fireworks explode, they produce colorful displays of light.