BSC 1005 Lecture 2: Chapter 2 Life's Chemical Basis (as PDF)
Document Summary
Atom, element, molecule, compound, subatomic particles, ion, isotope, orbitals, bonds, ph. Matter is anything that takes up space and mass. An element is a substance that cannot be broken down to other substances. Out of 94 naturally occurring elements, about 25 are essential for life. Abbreviations: c - carbon (coal), n - nitrogen, s - sulfur, na- - sodium (natrium), h - hydrogen. The most abundant elements in living organisms are carbon, hydrogen and oxygen. Carbon atomic number = 6, atomic mass = 12. 01. Hydrogen atomic number = 1, atomic mass = 1. 00797. Oxygen atomic number = 8, atomic mass = 16. Most of the hydrogen and oxygen are in the form of water. Carbon is the most important structural element in living organisms. Atom: the smallest portion of a substance that retains the properties of an element. Atomic nucleus: where p and n are tightly packed. Mass number : number of protons and neutrons.
