A)these are different elements.
B)oxygen atoms can have eight or 10 neutrons.
C)¹⁸O has two additional electrons in its outer shell.
D)¹⁸O is the form of oxygen that provides living cells with life.
E)only the common form of ¹⁶O can bond with hydrogen atoms to form H₂O.

A)the oxygen atom is more electronegative than the hydrogen atoms.
B)the oxygen atom has an overall negative charge with the hydrogen atoms having an overall positive charge.
C)unequal sharing of electrons results in a polar molecule.
D)All of the choices are correct.

A)the electron shell closest to the nucleus.
B)the outermost electron shell of an atom.
C)the volume of space in which electrons are most often found.
D)the original energy level of electrons in photosynthesis.