BIOA01H3 Chapter 2: Chapter 2 Study Guide

• School: UTSC
• Department: Biological Sciences
• Course: BIOA01H3
• Professor: Mark Fitzpatrick

Document Summary

Atom consists of a dense, positively charged nucleus & negatively charged electrons orbit around the nucleus. Atomic mass unit (amu) is mass of proton. Mass of electrons can be ignored because its mass is very low. Electron has negative charge equal to that of proton, -1. When number of proton equals number of electron, atom is neutral. Element is pure substance that contains only one kind of atom. 6 main elements found in organism: carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur. Mass number is the total number of proton & neutron in the nucleus. Atomic number is written at the lower left, mass number at the upper left. Isotope is element that has the same number of proton, but different number of neutron. Atomic mass/ atomic weight is the average mass of element based on the relative abundance of various isotopes. Radioisotope is unstable & gives off energy in the form of alpha, beta or gamma radiation from atomic nucleus.