Unit 3 Vocabulary Review

The rows in a periodic table that classify elements by number of electron shells 

Elements that have properties of both metals and nonmetals; sometimes called semiconductors

Elements that are solid, shiny, malleable, and good conductors of heat/electricity 

Columns in the periodic table that arrange elements by # of valence electrons

A table showing the chemical elements arranged according to their atomic numbers 

Electrons in the outermost energy level that determine how an atom reacts with other substances

Elements that aren't shiny, usually a gas, not malleable & poor conductors of heat/electricity 

The average mass of protons and neutrons in an atom 

A pure substance that cannot be separated into simpler ones by physical or chemical means

Unreactive non-metals in Group 18 on the Periodic Table 

A specific area where electrons of the same energy level are found