In the third period of the periodic table, sodium is followed by magnesium, aluminum, silicon, and phosphorus. which of these elements has the smallest atomic size?

Phosphorous would in fact be  the answer.

I'd go for the one that says that knees are fulcrums, lower legs are levers and the ankles hold loads.hope it ,happy homework/ study/ exam!

Answer it orbits high above earth to gain clearer images of light, it magnifies images relative to the human eye, it records most of the universe as it was in the past, not as it is now;