La Rioja PAU Chemistry Practice Questions - La Rioja PAU Chemistry Examination (Química 2o Bachillerato Universidad De La Rioja 2026) Exam

It increases because additional electron shells are filled. It decreases because effective nuclear charge increases while core electron shielding remains nearly constant. It remains constant because shielding by inner electrons completely cancels the increased nuclear charge. It decreases because electron-electron repulsions force electrons closer to the nucleus.