Group I Properties (Cambridge (CIE) O Level Chemistry): Exam Questions

Choose an element from the list below which best fits the description.

An element which reacts with cold water.

It is a solid at room temperature and exists as diatomic molecules, X₂.

It can form two oxides, XO and X₂O₃.

This element has a hydride of the type XH₃.

It has a macromolecular structure similar to that of carbon.

For each of the following, give the name of an element from Period 3 (sodium to argon), which matches the description.

An element which is gaseous at room temperature and pressure

An element that is added to water to kill bacteria.

An element that forms a basic oxide of the type XO.

An element that forms an amphoteric oxide.

An element that reacts vigorously with cold water to produce hydrogen.

The properties of the first four Group I elements are shown in the table.

Answer these questions using only the information in the table.

Describe the general trend in the melting points of the Group I elements.

Explain why it is difficult to predict the density of rubidium.

Deduce the state of rubidium at 45 °C. Explain your answer.

Francium, Fr, is a Group I element in Period 7 of the Periodic Table.

State the number of electrons in the outer shell of a francium atom.

Francium reacts with cold water.

Construct the equation for this reaction.

Francium is not used in school experiments.

Suggest why.

Francium forms an oxide with the formula Fr₂O.

A student says that francium oxide is a soft metal.

Explain why this statement is wrong.

Predict two physical properties of francium oxide.

The table shows the melting points of some Group I metals.

Describe the trend in melting point shown in the table.

Predict the melting point of rubidium.

Francium is also in Group I. A student predicts that the melting point of francium is 50 °C.

Explain why this prediction cannot be correct.

State which metal in the table is the most reactive with cold water.

Give a reason for your answer.

Lithium has the highest melting point of the metals in the table.

Suggest why lithium is still described as having a low melting point for a metal.

For each of the following, select an element from Period 4, potassium to krypton, which matches the description.

A metal that reacts rapidly with cold water to form a compound of the type M(OH)₂ and hydrogen.

Its only oxidation state is 0.

It has a macromolecular oxide, XO₂, which has similar physical properties to those of diamond.

This is one of the metals alloyed with iron in stainless steel.

It can be reduced to an ion of the type X^–.

It can form a covalent hydride having the formula H₂X.

Its soluble salts are blue and its oxide is black.

It is a liquid at room temperature.

Caesium is a metal in Group I of the Periodic Table.

Explain, in terms of electrons, why caesium forms an ion with a charge of 1+.

Q is a Group I metal. Q melts at 39 °C.

Potassium melts at 63 °C and caesium melts at 29 °C.

Deduce the position of Q in Group I relative to potassium and caesium.

Q and caesium are each added to a separate sample of cold water.

Predict which of the two reacts more vigorously.

Give a reason for your answer.

Construct the equation for the reaction of Q with cold water.

Use Q as the symbol for the metal.

The density of Q is 1.53 g cm^-3 and the density of caesium is 1.88 g cm^-3.

Explain whether this data supports your answer to part (b).

Element J is a neutral atom containing 37 electrons.

Element L is a neutral atom containing 55 electrons.

Explain how this information shows that J and L are both in Group I of the Periodic Table.

State which of J and L lies lower in Group I.

Give a reason for your answer.

Predict how the melting point of L compares with the melting point of J.

Predict how the density of L compares with the density of J.

Element M is a neutral atom containing 11 electrons.

Place J, L and M in order of increasing reactivity with cold water.

Give a reason for the order you have chosen.

A student investigates four metals, W, X, Y and Z. The results are shown in the table.

Identify the two metals that are in Group I.

Use two pieces of evidence from the table to support your answer.

Deduce which of the two Group I metals lies higher in the group.

Give a reason for your answer, using data from the table.

The student concludes that any metal which reacts with cold water must be in Group I.

Explain why this conclusion is not safe.

Name the gas produced when W reacts with cold water.

The table shows the densities of the five Group I metals from lithium to caesium.

Describe the general trend in density shown in the table.

Identify the two neighbouring metals in the table between which the density does not follow the general trend.

Explain why the density of the Group I metals can still be described as increasing down the group.

Francium lies below caesium in Group I.

Predict the density of francium.

State how certain this prediction can be.

State two properties of the Group I metals that change in the same direction at every step down the group.