Question

As the period number increases on the periodic table (moving from the top of the table to the bottom),
A.
the number of the principal energy level containing the valence electrons decreases.
B.
the atomic number decreases and the atomic mass increases.
C.
the number of the principal energy level containing the valence electrons increases.
D.
the atomic number increases and the atomic mass decreases.

Answer 1

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Answer 2

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Answer 3

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