Subatomic particles

This question is about atoms and ions.

The model of the atom has changed over time.

In an early model, scientists thought the atom was a tiny sphere that could not be divided.

Figure 1 represents this early model of the atom.

The discovery of a subatomic particle led to a change in the model in Figure 1.

Which was the first subatomic particle to be discovered?

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In a later model of the atom, most of the mass was concentrated in the centre of the atom.

What is the name of the centre of an atom?

Atoms contain three types of subatomic particle.

Draw one line from each subatomic particle to the relative charge of the particle.

What is meant by the ‘atomic number of an atom’?

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Table 1 shows information about two isotopes of an element.

Calculate the relative atomic mass (A_r) of the element.

Use the equation:

A = (mass number × percentage) of isotope A + (mass number × percentage) of isotope B

Give your answer to 1 decimal place.

An oxygen atom has eight electrons.

Complete Figure 2 to show the electronic structure of an oxygen atom.

Figure 2

Figure 3 represents two models of sodium chloride.

What are two advantages of model B compared with model A ?

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This question is about atoms, ions and elements.

Figure 3 shows the results of the alpha particle scattering experiment.

In the experiment, alpha particles were fired at gold foil.

Alpha particles are positively charged.

What two conclusions were made from the results?

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Particle X consists of:

• 35 protons

• 44 neutrons

• 36 electrons.

Why is particle X not an atom?

Answer in terms of subatomic particles.

Which is the correct representation of particle X ?

Use the periodic table.

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Group 7 elements are known as the halogens.

Table 2 shows the boiling points of some Group 7 elements.

Explain the increase in the boiling points of the Group 7 elements going down the group.

Chlorine reacts with fluorine to form a compound with the formula ClF₃

What is the type of bonding in the compound ClF₃?

Chlorine reacts with a solution of sodium bromide.

Complete the word equation for the reaction.

Explain why Group 7 elements become less reactive going down the group.

Potassium is in Group 1 of the periodic table.

What name is given to Group 1 elements?

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A potassium atom is very small.

What is the radius of a potassium atom?

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What name is given to the number of protons in an atom?

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Table 1 shows the name and the relative charge of the particles in a potassium atom.

Complete Table 1.

The electronic structure of a potassium atom is 2,8,8,1

Figure 1 represents the electronic structure of a potassium ion.

What is the charge on a potassium ion ?

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Figure 2 shows the melting points of some Group 1 elements.

Predict the melting point of potassium.

Potassium has two isotopes.

Table 2 shows the percentage (%) abundance of the two isotopes.

How is the relative atomic mass (A_r) of potassium calculated?

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All substances are made from atoms.

Figure 1 represents a beryllium atom.

What is the number of protons and the number of neutrons in the beryllium atom?

Figure 2 represents a beryllium ion.

What is the relative charge on a beryllium ion? Tick (✓) one box.

Figure 3 shows the arrangement of atoms in the three states of matter.

What state of matter is represented by state C in Figure 3 ? Tick (✓) one box.

What is the name of the process when state B changes into state A ?

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How can state B be changed into state C ?

Experimental evidence led to the scientific model of the atom changing over time.

Figure 4 shows three models for the atom.

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Complete the sentence. Choose the answer from the box.

The existence of neutrons was discovered by

Group 7 elements are known as the halogens. All atoms of Group 7 elements contain protons, neutrons and electrons.

What is the order of discovery of the proton, neutron and electron? Tick (✓) one box.

Table 1 shows the mass of a proton and of an electron.

Calculate how many times heavier a proton is than an electron.

A bromine atom can be represented as⁸¹₃₅Br.

What is the number of neutrons in this bromine atom?

What is the number of electrons in a bromide ion ?

Chlorine has two isotopes. Table 2 shows the percentage abundance of the two isotopes of chlorine.

Calculate the relative atomic mass (A_r) of chlorine.

Figure 4 shows the outer shells in one molecule of chlorine (Cl₂). Complete the dot and cross diagram to show the electrons in the outer shells.

This question is about Group 1 elements.

What are the Group 1 elements known as? Tick (✓) one box.

Figure 1 shows a lithium atom.

What is the number of electrons and neutrons in the atom of lithium?

What is the relative charge on a lithium ion? Tick (✓) one box.

Lithium is heated and then cooled in an experiment.

Two physical changes happen in the experiment. Draw one line from each stage to the physical change that happens in that stage.

Figure 2 represents the melting points of some Group 1 elements.

Figure 2

What is the melting point of caesium? Use Figure 2.

The melting point of potassium is 63 °C Draw a bar for the melting point of potassium on Figure 2.

Describe the trend of the melting points of the Group 1 elements in Figure 2.

The boiling point of sodium is 883 °C What is the state of sodium at 150 °C? Use Figure 2. Tick (✓) one box.

Figure 3 represents the electronic structure of a sodium atom and of a potassium atom.

Complete the sentence. Choose the answer from the box.

Potassium is more reactive than sodium because potassium more

Carbon can exist in a number of different structures.

What is the approximate radius of a carbon atom? Tick (✓) one box.

Figure 3 shows an atom of carbon.

Describe the atomic structure of this carbon atom. You should include the number of electrons, neutrons and protons.

In graphite the carbon atoms are held together by bonds.

Figure 4 represents part of the structure of graphite.

How many bonds does each carbon atom have in graphite? Use Figure 4. Tick (✓) one box.

What type of bonds hold the carbon atoms together in graphite? Tick (✓) one box.

Lubricants allow objects to slide over each other easily. Suggest why graphite can be used as a lubricant. Use Figure 4.

The two structures represent different forms of carbon. Draw one line from each structure to the form of carbon.

This question is about the periodic table.

Figure 1 shows part of Mendeleev’s version of the periodic table.

Which group of elements had not been discovered when Mendeleev’s version of the periodic table was published?

Figure 2 represents different models of the atom.

Which model represents the plum pudding model? Tick (✓) one box.

Which model resulted from Chadwick’s experimental work? Tick (✓) one box.

Potassium has different isotopes.

What is meant by ‘isotopes’? You should refer to subatomic particles.

Table 1 shows the mass numbers and the percentage abundance of two isotopes of potassium.

Calculate the relative atomic mass (A_r) of potassium. Give your answer to 1 decimal place.

This question is about the extraction of aluminium.

An aluminium atom is represented as: 27 A l 13 Give the number of electrons and neutrons in the aluminium atom.

Aluminium is extracted by the electrolysis of a molten mixture of aluminium oxide and cryolite. Figure 11 shows the cell used for the electrolysis.

Aluminium is produced by the reduction of aluminium oxide (Al₂O₃). What is meant by the term reduction?

Oxygen is formed at the positive carbon electrodes. Explain why the positive carbon electrodes must be continually replaced.

A substance conducts electricity because of free moving, charged particles. What are the free moving, charged particles in a:

• carbon electrode (made from graphite)

• molten mixture of aluminium oxide and cryolite

• metal wire?

Molten mixture of aluminium oxide and cryolite

This question is about the extraction of aluminium.

An aluminium atom is represented as: 27 A l 13 Give the number of electrons and neutrons in the aluminium atom.

Aluminium is extracted by the electrolysis of a molten mixture of aluminium oxide and cryolite. Figure 1 shows the cell used for the electrolysis.

Aluminium is produced by the reduction of aluminium oxide (Al₂O₃). What is meant by the term reduction?

Oxygen is formed at the positive carbon electrodes. Explain why the positive carbon electrodes must be continually replaced.

A substance conducts electricity because of free moving, charged particles. What are the free moving, charged particles in a:

• carbon electrode (made from graphite)

• molten mixture of aluminium oxide and cryolite

• metal wire?

Molten mixture of aluminium oxide and cryolite

This question is about the periodic table and argon.

What order did scientists use to arrange elements in early periodic tables? Tick (✓) one box.

In early periodic tables some elements were placed in the wrong groups. Mendeleev overcame some of these problems in his periodic table. Complete the sentence.

been discovered.

What is the name of the group that contains argon? Tick (✓) one box.

An atom of argon is represented as 40Ar 18 Determine the number of protons and the number of neutrons in one atom of argon.

39 38 Different atoms of argon are, Ar and Ar 18 18 What is the name given to these different atoms of argon?

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40 What is the electronic structure of an argon atom, Ar ? 18 Tick (✓) one box.

Why is argon unreactive?