Why are there only two elements in the first period of the periodic table?(1 point)

because the first two elements both start with H and are grouped together

because the next elements have other things in common and they need to be arranged together

because only two electrons can fit in the first orbit around the nucleus, and each period on the table is organized by number of orbits

because each row increases in atomic mass by a specific number, so anything over five is in the second row