Exam code: 5070
The diagram shows part of the structures of five substances, A, B, C, D and E.
Which one of these structures, A, B, C, D or E, is monatomic?
In structure E, no lines are drawn between the argon particles.
Explain, in terms of outer shell electrons, why argon atoms form no bonds with one another.
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Titanium is extracted by reacting titanium(IV) chloride with sodium.
The reaction is carried out under argon.
An argon atom has 18 electrons.
Deduce the electronic configuration of an argon atom.
State what the electronic configuration of an argon atom shows about its outer shell.
Explain why argon takes no part in the reaction between titanium(IV) chloride and sodium.
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Deep-sea divers breathe a mixture of helium and oxygen instead of air.
Helium is a noble gas in Group VIII.
State the number of electrons in the outer shell of a helium atom.
Neon and argon each have eight electrons in their outer shell.
Explain why the number for helium is different.
Explain why helium does not react with the oxygen it is mixed with.
Helium is described as monatomic.
State why helium is described in this way.
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A display sign is filled with neon gas at low pressure.
Neon is an unreactive, monatomic gas.
State what is meant by the term unreactive.
State what the particles inside the sign are.
A neon atom has the electronic configuration 2,8.
Explain how this configuration accounts for neon being unreactive.
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An atom of element X has the electronic configuration 2,8,8.
Deduce which group of the Periodic Table X belongs to.
Explain why X forms no compound with chlorine.
X is a gas at room temperature and pressure.
State whether the particles in the gas are atoms or molecules.
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For each of the following select an element from Period 4, potassium to krypton, that matches the description.
It is a brown liquid at room temperature.
It forms a compound with hydrogen having the formula XH4.
A metal that reacts violently with cold water.
It has a complete outer energy level.
It has oxidation states of 2 and 3 only.
It can form an ion of the type X-.
One of its oxides is the catalyst in the Contact Process.
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Helium, neon, argon, krypton, xenon and radon are noble gases in Group VIII.
Give the formula of radon gas.
Name the noble gas in the list whose atoms contain only two electrons in total.
Radon is very unreactive.
Use the electronic structure of radon to explain why.
Two isotopes of radon are shown.
(i) Give one similarity in the atomic structure of these two isotopes.
[1]
(ii) Give one difference in the atomic structure of these two isotopes.
[1]
Xenon forms a compound that contains only xenon, oxygen and fluorine.
The compound contains 22.1% oxygen by mass and 17.5% fluorine by mass.
Calculate the empirical formula of this compound.
A sample of neon has a volume of 21 dm3 at room temperature and pressure.
(i) The temperature of the sample is increased.
The pressure remains constant.
Describe and explain, using kinetic particle theory, what happens to the volume of the sample.
[1]
(ii) The pressure of the sample is increased.
The temperature remains constant.
Describe and explain, using kinetic particle theory, what happens to the volume of the Sample.
[1]
(iii) Calculate the mass of neon in the 21 dm3 sample.
Give your answer to two significant figures.
[2]
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A student is asked to explain why the noble gases are unreactive.
The student writes:
The noble gases have a stable octet.
This answer does not gain full credit.
State what the student has left out.
Write a corrected explanation of why argon is unreactive.
Explain why the student's wording is wrong for helium in particular.
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The noble gases are described as unreactive.
Chemists have nevertheless succeeded in making a small number of compounds of xenon, including XeF4.
State the number of electrons in the outer shell of a xenon atom.
Explain why xenon reacts only with great difficulty.
Fluorine is the most reactive non-metal.
Suggest why xenon forms a compound with fluorine rather than with a less reactive element.
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Sodium atoms form Na+ ions and chlorine atoms form Cl- ions.
Explain, in terms of outer shell electrons, why these two ions have opposite charges.
Argon atoms form neither Ar+ nor Ar- ions.
Explain why.
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A student is asked what the term monatomic means.
The student answers:
an element with one atom
State why this answer is not precise enough.
Write a more precise definition of the term monatomic.
Neon gas is written as Ne and not as Ne2.
Explain why, in terms of outer shell electrons.
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A student writes the following about the noble gases.
Every noble gas atom has eight electrons in its outer shell, so the noble gases are unreactive.
State whether the student's conclusion that the noble gases are unreactive is correct.
Explain what is wrong with the student's reasoning.
Rewrite the student's statement so that it is correct for every noble gas.
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The relative atomic mass of argon is 40.
A student states that the relative molecular mass of argon gas is 80.
Explain why argon gas has no relative molecular mass.
The student has assumed that argon gas is made of Ar2 particles.
Explain, in terms of electronic configuration, why Ar2 does not exist.
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