Zadanie 5g
Wzorowane na: Chemistry HL Paper 2, November 2023, TZ1, 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 has a low density, which is why it is widely used in aircraft and in specialized alloys.
Polecenie
Using nuclear charge, electron sub-levels and the shielding by filled inner shells, explain why the first ionization energy rises from sodium to magnesium but falls from magnesium to aluminium.
Sprawdź rozwiązanieUkryj rozwiązanieKlucz i punktacja
Odpowiedź z klucza
nuclear charge / number of protons increases «from Na to Mg to Al» ✔
Na and Mg: «outer electrons are in» the same sub-level / the same shielding by inner electrons, so the outer electron of Mg is held more strongly ✔
the outer electron in Al is lost from a p sub-level whereas that in Mg is lost from an s sub-level ✔
the outer electron in Al «3p» is higher in energy / is shielded by the 3s electrons «as well as the inner shells» ✔
Schemat punktowania
One mark for each of the four points. Do not accept explanations that rely only on the distance of the electron from the nucleus for M1 or M2.