Chemistry 0620 · IGCSE · Elements, compounds and mixtures
Elements, compounds and mixtures — practice question
A list of symbols and formulae is given below.
Br$_2$
CH$_4$
C$_2$H$_4$
Cl$^-$
CO$_2$
Cr$^{3+}$
Cu$^{2+}$
H$_2$
K$^+$
N$_2$
N$^{3-}$
O$_2$
SO$_4^{2-}$
Use these symbols and formulae to answer the questions that follow.
Each symbol or formula can be used once, more than once or not at all.
(a)[1]
State which symbol or formula matches:
(a) a molecule containing exactly five atoms
(b)[1]
(b) a diatomic molecule of an element in Group VII of the Periodic Table
(c)[1]
(c) an ion formed when an atom gains one electron
(d)[1]
(d) an ion which forms a green precipitate when a few drops of aqueous sodium hydroxide are added to it
(e)[1]
(e) a compound produced by the thermal decomposition of calcium carbonate
(f)[1]
(f) a product of photosynthesis.
Worked solution & mark scheme
This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “CH$_4$” …