Zadanie 1b
Wzorowane na: Chemistry HL Paper 3, May 2023, TZ1, pytanie 1(b). Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Darmowe konto pozwoli wrócić do niego później.
Informacja do zadań 1a-1f.
The table gives the first ionization energy and the first electron affinity of the elements in period 3 of the periodic table.
| Element | First ionization energy / kJ mol−1 | First electron affinity / kJ mol−1 |
|---|---|---|
| Na | 496 | −53 |
| Mg | 738 | +40 |
| Al | 578 | −42 |
| Si | 787 | −134 |
| P | 1012 | −72 |
| S | 1000 | −200 |
| Cl | 1251 | −349 |
| Ar | 1520 | +96 |
Polecenie
Explain the decrease in first ionization energy from magnesium to aluminium.
Sprawdź rozwiązanieUkryj rozwiązanieKlucz i punktacja
Odpowiedź z klucza
the electron removed is from a 3p sublevel in aluminium AND from a 3s sublevel in magnesium ✔
the 3p electron is higher in energy/further from the nucleus/partly shielded by the 3s electrons, so less energy is needed to remove it ✔
Schemat punktowania
M1: sublevel of the outer electron identified for both atoms. M2: reason why the 3p electron is easier to remove, based on the energy or position of the electron removed. Accept electron configurations of both atoms for M1.
Komentarz
The guide asks for an explanation based on the energy of the electron removed, not on the "special stability" of a filled sublevel.