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Infographic: the chemical elements organized according to the number of protons in each nucleus
The periodic table arranges all of the known elements in an informative array.
Ankylosaurus
Thick plates protected this massive dinosaur from predators.
seasons
The four periods of a year vary by location.
karnak
Egyptian pharaohs over the years each left their marks on this...
snow in Denmark
The winter solstice brings shifts in temperature and icy weath...
apatosaurus
For many years, this dinosaur was mistakenly called Brontosaurus.