Chemistry is the study of matter. Matter is composed of elements, elements are composed of atoms, and atoms are composed of particles with specific locations, charges, and mass. Energy is central to life, and is defined as the capacity to do work. Energy is stored in chemical bonds between atoms. Life depends on water and organic molecules. Hydrogen bonds in water impart unique life-supporting properties to water. Organic molecules are built around carbon atoms, and provide energy, structure, and important biological functions to living things.

Key Topics for this Chapter

		Atomic structure: protons and neutrons in the nucleus, electrons in shells
		Isotopes and ions
		Energy: potential and kinetic
		Chemical bonds: covalent, ionic, and hydrogen
		Water: a polar molecule, an important solvent, important to temperature regulation
		Acids, bases, pH scale, and buffers
		Organic molecules: carbohydrates, lipids, proteins, and nucleic acids

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