BIOL 1010 Chapter Notes - Chapter 2: Krypton, Radon, Ionic Bonding
Document Summary
Matter - anything that takes up space and has mass. Element - a substance that can not be broken down to other substances by chemical reactions. In other words, an element is composed of a single type of atom (i. e. , the smallest unit of matter having the physical and chemical properties of an element). 70 - 95% of all cells is water (h2o) 96% of living matter is made up of c, h, o, and n. other major elements include p, s, k, ca, mg, na, cl. Trace elements - required in minute quantities (< 0. 01%) but are nonetheless essential for life e. g. , fe, zn, i, mn, v . 0. 0005 x mass of a proton or neutron. Note: the mass of e- is ignored in computing total mass of an atom. * dalton is equivalent to an atomic mass unit (amu) Notation (mass number = sum of protons and neutrons) atomic mass.
