Which of the following statements is incorrect?

a - 0.25 mole of c has the same number of atoms as 0.25 mole of hg.
b - 1 mole of hydrogen atoms equals 1 mole of helium atoms.
c - 1 mole of carbon atoms and 1 mole of oxygen atoms are a 1: 1 ratio.
d - 1 mole of xenon atoms is more than 1 mole of neon atoms.

The correct option is D.
Mole is a measurement used in chemistry which allows us to measure out the same quantity of matter in different substances. Mole allows scientist to measure two substances, for instance, magnesium and sodium, which have equal amount of atoms. Thus, a mole of magnesium contains the same number of atoms as a mole of sodium.