In what group and period element with atomic number 13 belongs

The element with an atomic number of 13 is aluminum. It belongs in group 13 (the boron group). It belongs in period 3.

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.

answer:

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