BIOL 101 Lecture 2: Chemical Basis of Life
21 Jan 2019
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Document Summary
Anything that takes up space and has mass (solid, liquid, gas) Element- substance that cant be broken down into another substance by ordinary chemical means: only 92 naturally occurring elements, we are mostly made up of: carbon, hydrogen, oxygen and nitrogen (96%) Atomic theory states that elements consist of atoms. Atomic mass unit/weight- how many protons and neutrons. Atoms of the same element that differ in the number of neutrons. Have same number of protons but a different number of neutrons (different mass numbers) Radioactive isotope behavior is essential the same as a stable isotope of same element. 2 electrons fill the first orbit, 8 electrons fill each additional orbit. If an atom has more than 2 shells, the outer shell is most stables with 8 elements. In order for something to interact, less than full number of electrons in outer shell. Molecule- group of atoms bonded together (o2, h20, c6h12o6)
