Zadanie 5g
Wzorowane na: Chemistry HL Paper 2, November 2023, TZ2, pytanie 5(g). Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Darmowe konto pozwoli wrócić do niego później.
Informacja do zadań 5a-5h.
Aluminium is a low-density metal that is used in lightweight alloys.
Polecenie
Explain, in terms of nuclear charge, sub-levels and shielding, why magnesium has a higher first ionization energy than both sodium and aluminium.
Sprawdź rozwiązanieUkryj rozwiązanieKlucz i punktacja
Odpowiedź z klucza
the nuclear charge / number of protons increases from Na to Mg to Al ✔
the outer electrons of Na and Mg are in the same sub-level (3s) with similar shielding, so the first ionization energy increases ✔
the outer electron of Al is removed from a 3p sub-level, whereas that of Mg is removed from the 3s sub-level ✔
the 3p electron is higher in energy / is shielded by the 3s electrons «and the inner shells», so it is easier to remove ✔
Schemat punktowania
Award [1] for each marking point. Do not accept explanations based on the distance of the electrons from the nucleus, or on the special stability of filled sub-levels.