In the Periodic Table the far right column contains the noble gases, noble because they stay away from combining with other elements. Helium (Z = 2) has 2 electrons that fill a 1s shell. Neon (Z = 10) has 10 electrons (1s²·2s²2p⁶), and its outer 2p subshell is filled. Argon (Z = 18) is next (1s²·2s²2p⁶·3s²3p⁶), and krypton (Z = 36) follows it in the column. In addition to the argon electron configuration, krypton adds 4s, 3d, and 4p subshells. How many electrons are in each of these subshells?