The only element in the same period as helium is neon (Ne).
one element in the same group as oxygen
One element in the same group as oxygen is sulfur (S).
The element with an atomic number of 13
The element with an atomic number of 13 is aluminum (Al).
The only element in the same period as helium is hydrogen. In the periodic table, elements are arranged in rows called periods. Helium and hydrogen are both found in the first period, which means they have the same number of electron shells.
