Periodic Table Review Part 2

Led to reorganizing the period table on the basis of atomic number

Used letters used to represent each element and superscripts to represent number of atoms

These rows of elements are shown below the rest of the periodic table

Developed the law of octaves through arranging elements by atomic mass

Organized elements with similar characteristics in columns like the modern periodic table

Every element in this family has two or eight valence electrons

These elements make up Groups 3–12

Demonstrated that combustion requires the presence of oxygen

Include almost 80% of the elements

Ductile, malleable, and lustrous

Every element in this family has seven valence electrons

These elements make up Groups 13–16

Brittle solids with metallic luster

Exist naturally as a gas, liquid, or dull solid

These elements make up Group 2

Semiconductors

Every element in this family has one valence electron

First recognized groups of three elements with similar properties

Highly conductive and reactive

Possess four to eight valence electrons