In the early 1900s, a scientist named Alfred Wegener noticed how the continents seem to fit together and developed the Theory of Continental Drift. Continental drift is the theory that continents can drift apart from one other and have done so in the past. Wegner's theory also explained why fossils of the same plant and animal species are found on both sides of the Atlantic Ocean. In addition similar types of rock and evidence of the same ancient climatic conditions are found on several continents.
Wegner hypothesized that all the separate continents of today were once joined in a single landmass that he called Pangaea.
Metals are on the left side of the table and nonmetals are on the left with metalloids between them. And the noble gases are all in group 18 of the periodic table.
