Which statement describes a chemical reaction? a) reactants form products when atoms change state. b) products form reactants when atoms change state. c) reactants form products when atoms are rearranged. d) products form reactants when atoms are rearranged.

Place the elements below in order of decreasing ionization energy. aluminum(al) chlorine(cl) magnesium (mg) sulfur(s)

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.

What is the percentage of hydrogen in c2h4