B is the answer to your question
The metalloids are mostly concentrated in groups 14, 15, and 16. (Some simpler charts will show them as 4A, 5A, and 6A - take a look at the top of the periodic table your class uses to double-check).
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Answer:
c) Tìm những chất có hàm lượng đồng bằng nhau trong 4 chất : CuO, Cu2O, CuS, Cu2S.
Explanation:
C) 1e- is the answer because you need that in order to balance the charges
c) the government hires workers to install street lights
hope this helps!