FOCUS ON: Group 7 Elements - Halogens

Part 1 - Keywords:

1. Group 7 Elements

2. Halogens

3. Reactions

4. Electrons

5. Outer Shell

6. Non-metals

7. Molecules

8. Compounds

9. Reactivity

10. Relative Molecular Mass

11. Melting Point

12. Boiling Point

13. Displacement

Part 2 - Key Facts:

Halogens in Group 7:

• Group 7 elements, known as halogens, share similar reactions because they all have seven electrons in their outer shell. These non-metals form molecules consisting of pairs of atoms.

Compound Formation:

• Students should describe the nature of compounds formed when chlorine, bromine, and iodine react with both metals and non-metals.

Group 7 Trends:

• In Group 7, the relative molecular mass, melting point, and boiling point increase as you go down the group. Reactivity, however, decreases going down the group.

Displacement Reaction:

• A more reactive halogen can displace a less reactive halogen from an aqueous solution of its salt, showcasing the reactivity trend in Group 7.

Part 3 - Quick Quiz:

1. What is the common name for the elements in Group 7?

   a) Noble Gases

   b) Alkali Metals

   c) Halogens

   Answer: c) Halogens

2. Why do halogens in Group 7 have similar reactions?

   a) Same atomic number

   b) Same number of electrons in the outer shell

   c) Similar melting points

   Answer: b) Same number of electrons in the outer shell

3. How does the reactivity of halogens change going down Group 7?

   a) Increases

   b) Decreases

   c) Remains constant

   Answer: b) Decreases

Part 4 - Going Further:

Question: Discuss the implications of the trends in relative molecular mass, melting point, boiling point, and reactivity in Group 7. How do these trends impact the behaviour of halogens in chemical reactions?

Answer: The trends in Group 7 indicate that as you go down the group, halogens become heavier, have higher melting and boiling points, and are less reactive. This influences the nature of compounds they form and their ability to displace each other in reactions, showcasing the systematic behaviour of halogens.

Part 5 - Revision Tips: Focus on understanding the trends in Group 7 and how they influence the reactivity and behaviour of halogens. Practice describing the compounds formed by chlorine, bromine, and iodine with metals and non-metals.

Stay tuned for the next issue, where we'll explore more intriguing topics in GCSE Science.

Please note our last edition for 2023 will be on the 22nd December. We will be back in the new year from the 8th January. Enjoy your Winter break!