BIOLOGY 151 Lecture Notes - Lecture 3: Octet Rule, Ionic Bonding, Covalent Bond
Document Summary
Radioisotopes- give off alpha, beta, and gamma radiation from the nucleus. The radioactive decay transforms the atom, including changes in the number of protons. 8 electrons fill 2nd shell and so on. One dalton equals 1/12 the mass of a carbon atom. Mole- 1 mole of any element contains 6. 02 *10^23 atoms. Atoms can share electrons, or lose/gain electrons thus turning into molecules when they are bonded together. Octet rule: when atoms require 8 electrons in their outer shell. Hydrophobic interaction: interaction of non-polar substances in the prescience of polar substances (water) Van der waals interaction- interaction of electrons in nonpolar substances. Molecular weight of a compound- the sum of the atomic weights of all atoms in the molecule. Compound: a molecule made up of two or more element bonded together in a fixed ratio. Ions- electrically charged particles when atoms gain or lose electrons. Ionic bonds- formed by the electrical attraction of positive and negative ions.
