Question

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? (1 point)
Responses

Unlike all other elements, hydrogen and helium only have a maximum of 2 valence electrons
Unlike all other elements, hydrogen and helium only have a maximum of 2 valence electrons

Unlike all other elements, hydrogen and helium have very limited properties
Unlike all other elements, hydrogen and helium have very limited properties

Unlike all other elements, hydrogen and helium are gases
Unlike all other elements, hydrogen and helium are gases

Unlike all other elements, hydrogen and helium are not considered metals

Answer 1

Unlike all other elements, hydrogen and helium only have a maximum of 2 valence electrons

Explanation: Both are in the first energy level (n=1), which can hold at most 2 electrons (1s²). That makes their chemistry different from elements in higher periods and is why they are often shown separated from other groups.