CIE iGCSE Co-Ordinated Science C2.3 Isotopes Exam Style Questions Paper 3
Question
(a) State the name given to mixtures made from a metal with other elements.
(b) Iron is an element in Period 4 of the Periodic Table.
State the name of the collection of metals in Period 4 that contains iron.
(c) Describe the test used to identify iron(II) ions and give the observation for a positive result.
test ………………………………………………………………….
observation …………………………………………………….
(d) State the two substances that react with iron to make rust.
1 …………………………………………………………………………
2 ……………………………………………………………………….
(e) An isotope of iron has a proton number of 26 and a nucleon number of 58.
(i) Deduce the number of neutrons and the number of electrons in this isotope of iron.
neutrons = ………………………………………………………
electrons = ………………………………………………………
(ii) State the meaning of the term isotope.
(f) A teacher reacts dilute hydrochloric acid with four metals.
The observations are shown in Table 11.1.
Place the four metals in order of their reactivity from the most reactive to the least reactive.
most reactive ……………………………………………………………………..
least reactive ………………………………………………………………………
▶️Answer/Explanation
Ans : 11(a) alloy ;
11(b) transition elements / metals ;
11(c) aqueous sodium hydroxide ;
green precipitate ;
11(d) oxygen ;
water ;
11(e)(i) neutrons = 32 ;
electrons = 26 ;
11(e)(ii) atoms of the same element that have different numbers of neutrons ;
11(f) lithium calcium iron silver lithium and / or silver correct ;
all else correct ;
Question
(a) Two isotopes of iron are iron-54 and iron-56.
Both isotopes have a proton number of 26.
Iron-54 has a nucleon number of 54 and iron-56 has a nucleon number of 56.
(i) State the number of electrons in one atom of iron-54. (Sub-topic – C2.2)
▶️Answer/Explanation
Answer:
26
(ii) Determine the difference in the number of neutrons between an atom of iron-54 and an atom of iron-56. (Sub-topic – C2.3)
▶️Answer/Explanation
Answer:
2
(b) Iron is extracted from iron oxide using carbon monoxide. Carbon dioxide is also made. (Sub-topic – C6.3)
(i) Write the word equation for this reaction.
▶️Answer/Explanation
Answer:
Iron oxide + carbon monoxide → iron + carbon dioxide
(ii) State the substance that is oxidised in this reaction.
▶️Answer/Explanation
Answer:
Carbon monoxide
(c) Iron reacts with two other substances to make rust. (Sub-topic – C9.5)
(i) Name the element and the compound that react with iron when it rusts.
▶️Answer/Explanation
Answer:
Element: Oxygen
Compound: Water
(ii) Iron is coated with a material to prevent rusting.
Suggest one suitable material to use.
▶️Answer/Explanation
Answer:
Paint