Chemistry 0620 · IGCSE · Elements, compounds and mixtures

Elements, compounds and mixtures — practice question

A list of symbols and formulae is given below. Al$_2$O$_3$ C$_2$H$_5$OH CO$_2$ Fe$_2$O$_3$ H$_2$ He K$^+$ Li$^+$ N$_2$ Na$^+$ O$^{2-}$ Use only these symbols or formulae to answer the questions that follow. Each symbol or formula may be used once, more than once, or not used at all.
(a(i))[1]

State which symbol or formula denotes a monoatomic element.

(a(ii))[1]

State which symbol or formula represents an ion that produces a red colour in a flame test.

(a(iii))[1]

State which symbol or formula represents an element that serves as a fuel.

(a(iv))[1]

State which symbol or formula stands for a gas that contributes to climate change.

(a(v))[1]

State which symbol or formula represents an ion formed when an atom gains electrons.

(b)[2]

Complete the table to show the relative charges for a proton, neutron and electron.

(c)[2]

Choose the two correct statements about nitrogen and hydrogen in a mixture. Tick (✓) two boxes. The nitrogen and hydrogen mixture may be separated by physical methods. The nitrogen and hydrogen mixture is liquid at room temperature. The nitrogen and hydrogen atoms in the mixture are chemically combined. Air is mainly a mixture of nitrogen and hydrogen. Both nitrogen and hydrogen molecules have covalent bonding.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: $\text{He}$

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