Write the electron configurations for neutral atoms of gallium ( ga ), chlorine ( cl ), phosphorus ( p ), calcium ( ca ), and sulfur ( s ). electron configuration for ga : electron configuration for cl : electron configuration for p : electron configuration for ca : electron configuration for s : arrange the atoms according to both decreasing atomic radius and increasing first ionization energy (ie). largest radius smallest radius answer bank smallest first ie largest first ie answer bank select the statement(s) that explain(s) the relationship between the arrangement of elements by size and first ionization energy. the first set of paired electrons in a p subshell experience a large amount of electron-electron repulsion, making the fourth electron in a p subshell easy to remove. the third unpaired electron in a p subshell causes a lot of electron-electron repulsion among the orbitals, making the third electron in a p subshell easy to remove. a full s subshell is able to shield a newly filled p subshell from the nucleus, making the first electron in a p subshell easy to remove. the two arrangements are the same because ie of elements increases from left to right and the radii of elements decreases from left to right. a p subshell with only one unpaired electron is extremely stable, making the fifth electron in a p subshell easy to remove.