New
New
Year 9

Group 7 (halogens)

I can describe the pattern in reactivity of Group 7 non-metals and name the products of reactions between metals and halogens.

New
New
Year 9

Group 7 (halogens)

I can describe the pattern in reactivity of Group 7 non-metals and name the products of reactions between metals and halogens.

Lesson details

Key learning points

  1. The elements in Group 7 are all non-metals that have coloured vapours, most of which are toxic.
  2. The state of the elements at room temperature changes from gas to solid, down Group 7.
  3. Reactivity decreases down Group 7.
  4. Halogens react with Group 1 and 2 metals to form metal halides.
  5. Metal halides are soluble in water.

Keywords

  • Halogen - Elements found in Group 7 of the periodic table.

  • Group - Group is a column on the periodic table that corresponds to the number of electrons in the outer shell of an atom.

  • Halide - Refers to a compound of a halogen with another element or group.

  • Salt - Is a substance that forms when a metal reacts with a non-metal. These reactions typically produce solid substances that can dissolve in water, like table salt.

Common misconception

All halogens are gases at room temperature because they're non-metals; all halogens form toxic compounds.

Not all halogens are gases; bromine is a liquid and iodine is a solid at room temperature. While halogens are toxic, they also form essential compounds like table salt and disinfectants.

Demonstrate the states of halogens with visual aids or videos to highlight the differences among fluorine, chlorine, bromine, and iodine. Use everyday examples like table salt to explain halogens' beneficial uses, making the concept more relatable.
Teacher tip

Equipment

Spotting tiles, aqueous samples of each halogen, sodium halide salts, dropping pipettes or bottles.

Content guidance

  • Risk assessment required - equipment

Supervision

Adult supervision required

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

Lesson video

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6 Questions

Q1.
Starting with the first step, sort the following steps into the correct order for conducting a chemical experiment.
1 - Put on safety glasses.
2 - Mix the reactants.
3 - Record any observations.
4 - Clean up your workspace.
Q2.
Which element is in Group 7 and Period 3 of the periodic table?
Correct Answer: chlorine, Cl
Q3.
Which of the following statements correctly describes a salt?
A substance that turns blue litmus paper red.
Correct answer: A substance that forms when a metal reacts with a non–metal.
A substance with a pH greater than 7.
A substance that does not dissolve in water.
A substance that is always acidic.
Q4.
A substance with a pH of 12 is considered to be ...
acidic.
Correct answer: alkaline.
neutral.
sour.
Q5.
Which of the following describes a physical change?
rusting of iron
Correct answer: melting of ice
burning of wood
baking a cake
Q6.
The process of a substance in the solid state changing directly into the gas state is called ...
Correct Answer: sublimation

6 Questions

Q1.
Which of the following elements is a halogen?
sodium
Correct answer: chlorine
magnesium
carbon
oxygen
Q2.
What happens to the reactivity of the halogens as you go down Group 7?
increases
Correct answer: decreases
stays the same
fluctuates
Q3.
The state of iodine at room temperature is ...
Correct answer: solid.
liquid.
gas.
Q4.
Match the following halogens to their correct description.
Correct Answer:fluorine,A pale yellow gas at room temperature.

A pale yellow gas at room temperature.

Correct Answer:chlorine,A pale green gas at room temperature.

A pale green gas at room temperature.

Correct Answer:bromine,A reddish–brown liquid at room temperature.

A reddish–brown liquid at room temperature.

Correct Answer:iodine,A purple–black solid at room temperature.

A purple–black solid at room temperature.

Q5.
Which of the following are products of the reaction between a Group 1 metal and a halogen?
metal hydroxide
Correct answer: metal halide
hydrogen gas
water
Q6.
Name the product of the reaction between potassium and bromine.
Correct Answer: potassium bromide