Miller & Levine Biology - CHapter 2 Notes
Subject:
Biology [1]
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Chapter 2: The Chemistry of Life The Nature of Matter Atoms are the smallest, indivisible particles of matter First theorized by Democritus about 2500 years ago (ya) Atoms made of two parts that consist of a combination of three different subatomic particles Nucleus is the ?core? of an atom Protons have a positive charge Neutrons have a neutral charge Electron cloud Divided into orbitals (layers) First layer is smallest and contains maximum of 2 electrons Second layer contains maximum of 8 electrons Third layer maximum of 8 electron Elements and Isotopes Element is a pure substance consisting of a single type of atom Isotopes are atoms of the same element with different numbers of neutrons