What is the answer to this question?

13. a covalent bond between two atoms is likely to be polar if: a. one of the atoms is much more electronegative than the other. b. the two atoms are equally electronegative. c. the two atoms are of the same element. d. the bond is part of a tetrahedrally shaped molecule. e. one atom is an anion.

Consider the story you just read. all but one of the choices below indicate that something is living.

Calculate the percent composition by mass of each element in al(oh)3. use at least three significant figures.