NATS 1610 Lecture Notes - Unified Atomic Mass Unit, Electron Shell, Unpaired Electron
Document Summary
The living body- chemical basics tuesday october 8, 2013. Over 90% of the human body is composed of 4 elements: carbon (18%), nitrogen (3%), Atomic number: number of protons in nucleus (usually written as subscript in bottom left) Atomic weight: weight of protons plus neutrons (protons and neutrons = 1 atomic mass unit) (upper left subscript: electrons are light and have almost no mass. Electrically neutral atoms: have the same number of protons and electrons. Atoms react with other elements to form compounds and molecules: molecules: group of 2 or more atoms held together in a stable association, compounds: molecules containing more than one type of elements, ex. Water, always has one oxygen and 2 hydrogen atoms: chemical bonds: hold atoms together in molecules or compounds. Use symbols for elements when writing formulas: c6 h12 o6 (6carbons, 12 hydrogen"s, 6 oxygen"s, chemical equations shows reaction: reactants products, 6co2 + 6h2o c6h12o6 + 6o2 (general equation for photosynthesis, reactants.
