The periodic table

Atoms of neon are made up of subatomic particles.

Figure 14 shows some information about the subatomic particles in neon atoms.

Complete Figure 14 with the missing information.

All atoms of neon have an atomic number of 10.

Describe what information about the number of subatomic particles can be obtained from the atomic number of neon.

Explain why atoms of neon are electrically neutral.

*(b) The structure of the periodic table and the position of the elements in the periodic table are linked to the electronic configuration of the elements.

Figure 15 shows the structure of the periodic table and the first 12 elements with their atomic numbers.

group

Use the first 12 elements shown in Figure 15 to explain

• how the structure of the periodic table is linked to the electronic configuration of the atoms of the elements

• how the arrangement of the elements is linked to their electronic configuration.

Figure 8 shows some information about an atom of chlorine.

35 C l 17

Figure 8

State the number of protons, neutrons and electrons in this atom.

Chlorine reacts with silicon to form silicon chloride.

A sample of silicon chloride contains 1.4 g of silicon atoms and 7.1 g of chlorine atoms.

Calculate the empirical formula of this sample of silicon chloride.

(relative atomic masses: Si = 28, C l = 35.5)

empirical formula =_........

The modern periodic table is organised into groups and periods.

State in which group and in which period of the periodic table silicon is found.

You should use the periodic table to help you answer this question.

Describe two differences between Mendeleev’s periodic table and the modern periodic table.

The relative atomic mass of argon is 40 and the relative atomic mass of potassium is 39 but potassium appears after argon in the periodic table.

State why potassium appears after argon in the periodic table.

Potassium reacts with water to form two products.

Give the formulae of both products.

The reaction of potassium with water is exothermic.

On Figure 9, draw and label the reaction profile diagram for this reaction, labelling the activation energy.

Some reactions are endothermic.

Explain, in terms of bond breaking and bond forming, why some reactions are endothermic.

Ethene reacts with hydrogen chloride.

C l H

Figure 10 shows the bond energies for the different bonds in the three molecules in the reaction.

Calculate the energy change for this reaction.

energy change =_........ kJ mol

Magnesium is a metal.

State one physical property of magnesium.

Which element is in the same group of the periodic table as magnesium? Use the periodic table to help you answer this question.

Magnesium atoms have 12 electrons.

Complete the electronic configuration of a magnesium atom.

The electronic configuration of a chlorine atom is 2.8.7

Explain how the electronic configuration of chlorine is linked to its period in the periodic table.

1.20 g of magnesium reacts completely with 3.55 g of chlorine to form magnesium chloride.

Calculate the empirical formula of the magnesium chloride.

(relative atomic masses: Mg = 24.0, C l = 35.5)

You must show your working.

Sodium reacts with chlorine to form sodium chloride, which contains ionic bonds.

Hydrogen reacts with chlorine to form hydrogen chloride, which contains covalent bonds.

Figure 9 shows dot and cross diagrams of these compounds.

Describe the differences between an ionic bond and a covalent bond.

Figure 6 shows some information about the group 1 metals.

Explain, in terms of their electronic configurations, why these metals are placed in group 1 of the periodic table.

Which row shows two correct properties of group 1 metals?

The word equation for the reaction of potassium with bromine is

potassium + bromine potassium bromide

Add the missing state symbol and balance the equation for this reaction.

A sample of potassium contains three isotopes, potassium-39, potassium-40 and potassium-41.

Explain the meaning of the term isotopes.

This sample of potassium contains

93.25% potassium-39

0.02% potassium-40

6.73% potassium-41

Calculate the relative atomic mass of this sample of potassium.

An atom of aluminium has an atomic mass of 27.

Aluminium has an atomic number of 13.

State the number of electrons, neutrons and protons in this atom.

Aluminium reacts with bromine to form aluminium bromide. A sample of aluminium bromide contains 1.35 g of aluminium atoms and 12.00 g of bromine atoms.

Calculate the empirical formula of this sample of aluminium bromide.

(relative atomic masses: A l = 27.0, Br = 80.0)

Gallium is in the same group in the periodic table as aluminium and in the same period in the periodic table as bromine.

State in which group and period of the periodic table gallium can be found.

You may want to refer to the periodic table.

Gallium had not been discovered when Mendeleev created his first periodic table.

Figure 9 shows some properties of gallium that Mendeleev predicted and some of the actual properties of gallium.

Describe how Mendeleev predicted these properties of gallium.

This question is about elements in group 1 of the periodic table.

Figure 3 shows the symbols of the first three elements in group 1 of the periodic table and their melting points.

Use the periodic table to answer these questions.

Give the symbol of another element in group 1.

Give the atomic number of lithium.

Describe the trend in the melting points of the elements in Figure 3.

The elements in group 1 react very vigorously with water.

A student suggests this method to see what happens when sodium reacts with water.

step 1 put on safety glasses and a laboratory coat

step 2 cut a 2 cm2 cm2 cm cube of sodium

step 3 put a few drops of water in the container shown in Figure 4

step 4 add the sodium to the water in the container and observe the reaction

Figure 4 shows a diagram of the container the student suggested for step 3.

Give the name of the container shown in Figure 4.

A teacher says that the method is not safe because the reaction is too vigorous.

Explain changes that could be made to step 2 and to step 3 that would make the method safer.

step 2: change and explanation

step 3: change and explanation

This question is about the noble gases.

State, in terms of outer shell electrons, why the noble gases are unreactive.

Figure 4 shows an airship, filled with helium, floating above the ground.

Helium, hydrogen and krypton are gases. Figure 5 shows the reactivity and density, at room temperature and pressure, of helium, hydrogen and krypton.

The density of air is 0.001225 gcm^–3.

Helium is used in airships.

Explain why hydrogen and why krypton are not used in airships.

Mendeleev produced one of the earliest periodic tables.

State why he could not include any of the noble gases in his periodic table.

Figure 6 shows the boiling points of some of the noble gases.

Complete the bar chart to show the boiling points of neon and argon.

Predict the boiling point of xenon.

boiling point of xenon =_........

Fluorine, chlorine, bromine and iodine are elements in group 7 of the periodic table.

State the name given to the group 7 elements.

Name one other element that is in group 7. Use the periodic table on the back of this exam paper to help you.

Which element is liquid at room temperature and pressure?

Which element is dark-grey in colour at room temperature and pressure?

Tin reacts with chlorine to form tin chloride. A sample of tin chloride contains 1.19 g of tin and 1.42 g of chlorine.

Calculate the empirical formula of this tin chloride.

(relative atomic masses: C l = 35.5, Sn = 119.0)

You must show your working.

empirical formula of this tin chloride =_........

Tin also reacts with fluorine. The reaction between fluorine and tin is much more vigorous than the reaction between chlorine and tin.

Figure 8 shows the electronic configurations of fluorine and chlorine.

Explain, in terms of their electronic configurations, why fluorine reacts with tin more vigorously than chlorine reacts with tin.

In the 19th century, Mendeleev arranged the elements known at the time to form his periodic table. Mendeleev’s periodic table is different from the modern periodic table.

State one difference between Mendeleev’s periodic table and the modern periodic table.

Aluminium oxide reacts with hydrochloric acid to form a salt and water.

State the name of the salt formed.

In this reaction aluminium oxide is a base.

State the type of reaction that takes place when an acid reacts with a base.

Gallium, Ga, is in the same group of the modern periodic table as aluminium.

The formula of aluminium oxide is Al₂O₃.

Predict the formula of gallium oxide.

Gallium oxide has a very high melting point. Gallium oxide does not conduct electricity when solid but does conduct electricity when molten.

What type of substance is gallium oxide?

Figure 5 shows the changes of state for gallium and the arrangement of particles in liquid gallium.

Complete the boxes for solid gallium and gaseous gallium by drawing the arrangement of the particles in each of these physical states.

Give the name of the change of state labelled Y in Figure 5.

Gallium metal is a conductor of electricity.

Explain how metals conduct electricity.

An atom of potassium has atomic number 19 and mass number 39.

Give the electronic configuration of this potassium atom.

This potassium atom forms the ion K⁺.

Which row shows the number of protons and the number of neutrons in this potassium ion, K⁺?

Potassium and caesium are in the same group of the periodic table.

Explain, in terms of electrons, why potassium and caesium are in the same group.

Fluorine boils at –188C. There are forces between fluorine molecules.

Explain, in terms of these forces, why the boiling point of fluorine is low.

Potassium reacts with fluorine to form potassium fluoride. Potassium fluoride is a solid.

Complete the balanced equation for this reaction and add the state symbols.

What are the elements in group 1 of the periodic table called?

Figure 14 shows the melting points and boiling points of elements in group 7 of the periodic table.

Give, using Figure 14, the boiling point of bromine.

State which two elements from Figure 14 are solids at room temperature.

Using the letters A, E, G, J, X and Z

give the letters of the two elements that are non-metals

give the letters of two elements in period 2

give the letter of an element that normally forms an ion with a charge of +1.

Element E has an atomic number of 5. In a sample of E there are two isotopes. One isotope has a mass number of 10 and the other isotope has a mass number of 11.

Explain, in terms of subatomic particles, what is meant by the term isotopes.

All atoms of element E in this sample contain

Element X has an atomic number of 18.

State the electronic configuration of an atom of element X.

In an experiment, 3.5 g of element A reacted with 4.0 g of element G to form a compound.

Calculate the empirical formula of this compound. (relative atomic masses: A = 7, G = 16)

You must show your working.

(a) Atoms contain electrons, neutrons and protons.

Draw one line to link each particle to its correct relative charge.

Which of the following is the relative mass of a proton?

Argon is in group 0 of the periodic table.

Identify, using the periodic table on the back cover of this paper, which of these elements is in the same period as argon.

Figure 4 shows the atomic number and mass number of two isotopes of argon.

Describe the structure of an atom of argon-38 and of an atom of argon-40.