Zadanie 2b
Wzorowane na: Chemistry HL Paper 2, May 2022, TZ2, pytanie 2(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 2a-2b.
Evidence for the arrangement of electrons in atoms comes from trends in ionization energy and from emission spectra.
Polecenie
The diagram represents the electron energy levels in a hydrogen atom.
(i) Suggest two features of the behaviour of electrons in atoms that this energy level model cannot explain or represent.
(ii) Draw an arrow, labelled X, on the diagram to represent the electron transition for the ionization of a hydrogen atom whose electron is in the n = 2 level.
(iii) Draw an arrow, labelled Z, on the diagram to represent the emission transition that produces the visible light of lowest energy.
Sprawdź rozwiązanieUkryj rozwiązanieKlucz i punktacja
Odpowiedź z klucza
(i) any two of:
it does not show sublevels / orbitals ✔
it only applies to atoms with one electron / hydrogen «electron–electron repulsion is ignored» ✔
it does not explain why only certain energy levels are allowed ✔
it does not take into account the interaction of the atom with other atoms or with external fields ✔
it does not show the probability of finding the electron at different positions ✔
(ii) upward arrow labelled X starting at the n = 2 line and ending at n = ∞ ✔
(iii) downward arrow labelled Z from the n = 3 line to the n = 2 line ✔
Schemat punktowania
(i) [1] for each valid limitation, maximum [2]; do not accept «the diagram does not show distance from the nucleus». (ii) arrow must start at n = 2 (not n = 1) and go up to the top line. (iii) the arrow must point downwards from n = 3 to n = 2.