Two of most unique elements on the periodic table are hydrogen and helium. What makes them so unique and removed from the other groups on the periodic table?
a. Unlike all other elements, hydrogen and helium are gases
b. Unlike all other elements, hydrogen and helium are not considered metals
c. Unlike all other elements, hydrogen and helium only have a maximum of 2 valence electrons
d. Unlike all other elements, hydrogen and helium have very limited properties