Why are there only two elements in the first period of the periodic table? (1 point) because each row increases in atomic mass by a specific number, so anything over five is in the second row
O because the next elements have other things in common and they need to be arranged together
because the first two elements both start with H and are grouped together
o 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