The atoms on the surface of a metal tend to react with the oxygen in the air and form an oxide coating. This coating, or tarnish, appears dull and less shiny, and it decreases the ability of a metal to react. Did you observe this? Explain.

thats a little if u want the answer just look it up on google thats what i do haha : )

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.