BIOL 1107 Chapter 2: Chapter 2
Document Summary
Matter: anything that takes up space and has mass, including living organisms. Element: substance that cannot be broken down to other substances by chemical reactions. Ex. if we break it down only get sodium. Compound: substance consisting of two or more elements in fixed ratio. Nacl = table salt which is a compound. Emergent properties compound has different characteristics from elements after combining together. 25 required for life essential elements. Most living matter (96%) is made of carbon, hydrogen, oxygen and nitrogen. Most of the remaining 4% is ca, p, k, s. Trace element: present only in minute amounts. Several other elements, called trace elements, are required in only minute quantities. Element properties depend on the structure of its atoms. Atoms smallest unit of matter (properties of elements) are composed of subatomic particles. Proton and neutron together atomic nucleus (center of atom) Rapidly moving electrons form negatively charged (electrons) cloud around nucleus. Neutron and proton have almost same mass.
