When did our ancestors start to eat meat regularly? Fossilized teeth get us closer to the answer
Atoms of the same element can have different versions, called isotopes, which have the same number of protons but different ...
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Elements, Mixtures and Compounds
An element is a substance that is made up of only one kind of atom. The atoms in a particular element are the same as each other, and they are different from the atoms of all other elements.
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Rutherford and Bohr describe atomic structure
Atoms with less than the maximum number in their outer shells are less stable than those with "full" outer shells. Elements that have the same number of electrons in their outermost shells appear ...