Why does the second row of the periodic table have 8 elements​

short asnwer:

here are 8 elements in period 2 because all those elements have electrons in the second shell and no electrons in the third shell.

Explanation:

There are certain rules for arranging atoms in shells 1) Maximum number of electrons in a shell is given by the formula 2n^2. 2) The outermost ( valence) shell can accomodate only 8 electrons.

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Explanation:

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answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.