Zadanie 1g
Wzorowane na: Chemistry SL Paper 2, May 2022, TZ1, pytanie 1(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 1a-1g.
Calcium turnings burn in air to form mainly calcium oxide, CaO. A small amount of calcium nitride, Ca3N2, is also formed according to the equation:
3 Ca(s) + N2(g) → Ca3N2(s)
Polecenie
State the type of bonding in calcium, nitrogen and calcium nitride, and how the valence electrons produce each type of bonding.
Sprawdź rozwiązanieUkryj rozwiązanieKlucz i punktacja
Odpowiedź z klucza
calcium: metallic ✔ AND valence electrons are delocalized throughout the lattice «and attracted to the cations» ✔
nitrogen: covalent ✔ AND valence electrons are shared between the atoms «three pairs shared in N2» ✔
calcium nitride: ionic ✔ AND valence electrons are transferred from calcium atoms to nitrogen atoms ✔
Schemat punktowania
[1] for all three bonding types correct. [1] for each correct description of how the valence electrons produce the bonding (three marks). Accept a “sea” of electrons for the metallic description. Accept calcium electrons lost AND nitrogen electrons gained for the ionic description.