The Chemistry Of Life
Subject:
Biology [1]
Tags:
Chemistry [2]
Chemical bonding [3]
Atomic physics [5]
Chemical bond [8]
Valence electron [9]
Covalent bond [11]
molecule [12]
Atomic orbital [13]
Technology [14]
Chapter 2 The Chemical Context of Life Elements and Compounds An element is a substance that cannot be broken down to other substances by chemical reactions A compound is a substance consisting of two or more elements in a fixed ratio Sodium Chlorine Sodium chloride Essential Elements of Life Carbon, hydrogen, oxygen, and nitrogen make up 96% of living matter Trace elements are those required by an organism in minute quantities LE 2-3 Nitrogen deficiency Iodine deficiency LE 2-4 Nucleus Electrons Cloud of negative charge (2 electrons) Atomic Number and Atomic Mass Atoms of the various elements differ in number of subatomic particles Atomic number Mass number Atomic mass Isotopes Atoms of an element have the same number of protons but may differ in number of neutrons