Describe subscripts in chemical equations.
1 answer:
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Answer:
7 valence electrons
Explanation:
Astatine has the atomic number 85. Thus, its electron configuration is:
[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵
As we can see, in the last level (6) it has 2 + 5 = 7 electrons, that is, astatine has 7 electrons in its valence shell. In the Lewis dot structure (attached) we write 3 pairs of electrons and 1 unpaired electron around the symbol of At.
