Group 7: the halogens

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?

Tick () two boxes.

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.

Tick () one box.

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.

Halogens are elements in Group 7 of the periodic table.

Calcium reacts with chlorine to produce calcium chloride.

Explain what happens to calcium atoms and to chlorine atoms when calcium reacts with chlorine to produce calcium chloride.

Explain why chlorine is more reactive than bromine.

Table 4 shows the boiling points of four hydrogen halides.

Describe how the boiling points of the hydrogen halides change as the relative formula mass changes.

This question is about Group 7 elements.

What are the Group 7 elements known as?

Why do Group 7 elements react in similar ways?

Figure 3 shows the structure of a molecule of chlorine oxide.

What is the molecular formula of the chlorine oxide molecule in Figure 3 ?

Figure 4 shows the melting points of some Group 7 elements.

The melting point of fluorine is –220 °C Complete Figure 4. You should:

• complete the scale on the y-axis

• draw the bar for the melting point of fluorine.

Explain the trend in the melting points of the Group 7 elements. Use Figure 4.

What is the state symbol for bromine at –50 °C? Use Figure 4. Tick (✓) one box.

Evaporation and boiling occur at the surface of bromine at its boiling point. Name one more process that happens at the surface of bromine at its boiling point.

This question is about gold and compounds of gold. In the alpha particle scattering experiment alpha particles are fired at gold foil. Alpha particles are positively charged. Figure 4 shows the results.

Some alpha particles are deflected. Complete the sentence. Choose the answer from the box.

Some alpha particles are deflected because the nucleus of the atom is.

Why are most alpha particles not deflected? Tick (✓) one box.

What was one conclusion from the alpha particle scattering experiment? Tick (✓) one box.

Gold reacts with the elements in Group 7 of the periodic table.

What are Group 7 elements known as? Tick (✓) one box.

Fluorine, chlorine and bromine react with gold. Which element will be the most reactive with gold?

Tick (✓) one box.

3.94 g of gold reacts with chlorine to produce 6.07 g of gold chloride. The word equation for the reaction is: gold + chlorine → gold chloride Calculate the mass of chlorine that reacts with 3.94 g of gold.

Calculate the relative formula mass (M_r) of gold chloride (AuCl₃). Relative atomic masses (A_r): Cl = 35.5 Au = 197

This question is about the halogens.

Which group in the periodic table is known as the halogens? Tick one box.

A fluorine atom has 7 electrons in the outer shell. Figure 8 shows part of a dot and cross diagram to represent a molecule of

Complete the dot and cross diagram. You should show only the electrons in the outer shells.

Chlorine reacts with potassium bromide solution. Complete the word equation.

What type of reaction happens when chlorine reacts with potassium bromide solution? Tick one box.

Complete the sentence. Choose the answer from the box.

Chlorine is more reactive than bromine.

How does the size of a chlorine atom compare with the size of a bromine atom? Complete the sentence. Choose the answer from the box.

Give a reason for your answer to question 02.6

Fluorine reacts with chlorine to produce ClF₃ Balance the chemical equation for the reaction.

Explain why fluorine is a gas at room temperature. Use the following words in your answer: energy forces molecules weak

This question is about the halogens.

Write the state symbol for chlorine at room temperature.

Figure 4 represents one molecule of fluorine. Complete the dot and cross diagram on Figure 4 You should show only the electrons in the outer shells.

19 A fluorine atom can be represented as 9 F What is the total number of electrons in a fluorine molecule (F₂)? Tick one box.

Aluminium reacts with bromine to produce aluminium bromide. Complete the balanced chemical equation for this reaction.

When chlorine reacts with potassium bromide, chlorine displaces bromine.

Explain why chlorine is more reactive than bromine.