Question

predict the size of the astatine atom compared to that of tellurium

Answer 1

Astatine atom is bigger because as you move down the periods a shell of electrons is added for every one period you move down. Astatine has more protons but e- shells matter more for determining the size of an atom.

Answer 2

atomic size increases as you move \(\downarrow\) periodic table, and also as you move \(\leftarrow\) the periodic table.