Question

Helium is in group 18 of the periodic table. How is helium different from the other elements in this group?

Answer 1

Helium is different from the other elements in group 18, also known as the Noble Gases, because it has only two electrons in its outermost energy level (valence electrons), while the other elements in the group have eight valence electrons. This makes helium chemically inert and less likely to form compounds with other elements. Additionally, helium has the lowest atomic number and atomic mass in the group, with a completely filled first energy level, whereas the other elements have additional energy levels.