CHM 103 Lecture Notes - Atomic Orbital, Periodic Trends, Electron Configuration
Document Summary
A periodic table is a tabular arrangement of elements based on their properties things going across are group/family things going down are periods these periods/groups have similar chemical properties. A vertical column of elements that have similar properties traditionally designated by a roman numeral and a letter (either a or b) at the top of the column. Designated only by a number from 1 to 18. Group 1a - halogens have same number of outer electrons. As you go down the periodic table the mass increases. Horizontal row of elements arranged according to increasing atomic numbers. Periods are numbered from top to bottom of the periodic table. Elements 58-71 and 90-103 are not placed in their correct periods, but are located below the main table it is thought that they will be able to make or find element 118. Examples of group and period location for elements. Calcium, ca, element 20: group iia, period 4.