CHEM 110 Lecture 1: Matter and Energy
Document Summary
Of ce hour: tues, thurs 10:30-11:30am at 220c whitmore. The properties of matter on the types and arrangements of atoms, ions, and molecules. Change in matter involves the reorganization of atoms, ions, and molecules, depending on external conditions. Energy is exchanged in the making and breaking of bonds. An atom is made of protons, neutrons, and electrons. Nuclear symbol: mass number on top of the atomic number! Isotopes- atoms of an element with the same number of protons but different number of neutrons in the nucleus. Ions- charged species with an excess or de ciency of electrons as compared to the number of protons in the nuclei. Anion- an ion with a net negative charge. Cation- an ion with a net positive charge. Atomic mass unit (amu)- 1/12 mass of a carbon - 12 atom, 1amu=1. 66054*10^-24g. Atomic mass- the average of the masses of its naturally occurring isotopes weighted according to their andantes. Atomic weight= sum of(isotopic mass*fractional natural abundance)
