CHEM 1500 Lecture Notes - Lecture 9: Nonmetal, Atomic Number, Bromine

• School: York University
• Department: Chemistry
• Course: CHEM 1500
• Professor: Valeria Tsoukanova

Document Summary

Atomic number, z, is above the symbol. Weighted average atomic mass, a, below the symbol. If a has no brackets naturally occurring element. If [a] has brackets element produced synthetically. List elements in order of increasing atomic number, z (left to right) Trends (going across a period (left to right) Number of shells increases by 1 each time. Number of valence electrons increase by 1. The number of elements in a period is equal to the number of electrons that the valence shell can accommodate. There are main group elements and transition metals. (main group elements are the elements in the tallest groups) Also form bases, but less soluble than alkali metals. Can form salts with nearly all the metals of the periodic table. They are unique because they do not participate in chemical change/reactions. Are shiny solids (except for mercury which is a liquid at room temperature) Gases: hydrogen, noble gases, fluorine, chlorine, oxygen, nitrogen.