Is it Christmas yet? Where are my presents? Chapter 12 Is it Christmas yet? Where are my presents?
Periodic Something that repeats in a regular pattern
period Horizontal rows on the periodic table
group A vertical column of elements – they share properties or traits like a family
Periodic law The chemical and physical properties of the elements change with their atomic number.
Alkali metals Group I on the chart Very active metals
Alkali earth metal Elements that are in group 2. Silvery but not as reactive as the group 1 metals
halogen Combine with metals to make salt Group 17 or 7
Noble gas Nonmetals that don’t want to react with other elements They don’t play well with others – they want to be left alone.
Transition Metals Less reactive of all the other metals Usually silver in color Properties vary widely
hydrogen Has properties unlike any other group Act more like nonmetals than metals
metalloids Semiconductors Anything touching the stairs
lanthanides Gives us the color red on computer screens Used to make steel – very shiny