Atoms of elements that are in the same Mendeleev left gaps in his ...

11. The three main groups of elements are metals, nonmetals, and A. alkali metals B. semiconductors 13. Most elements on the left side of the periodic table are A. nonmetals B. metals 14. Each element in an element family shares the same A. number of valence electrons B. atomic number 15. Elements in an element family have similar A. atomic weights ................
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