Page 140 - Knowledge Organiser Yr9 24-25

Knowledge Base: Science C1: Atomic Structure and the Periodic Table Year 9
12. Group 1
12.1
What is the name of elements in group 1?
The alkali metals.
12.2
Why do elements in group 1 have very similar properties?
They all have one electron in their outer shell.
12.3
Describe the trend in reactivity as you go down group 1.
Reactivity increases.
12.4
Why does reactivity change as you go down group 1?
As you go down the group:
• the distance between the outer
electron and the nucleus increases.
• the attraction between the positive
nucleus and the negative outer
electron decreases.
• the outer electron is more
easily lost.
12.5
What is produced in a reaction between a group 1 metal and water?
Metal hydroxide and hydrogen (gas).
12.6
What is produced in a reaction between a group 1 metal and oxygen?
Metal oxide (white solid).
12.7
What is produced in a reaction between a group 1 metal and chlorine?
Metal chloride (white solid).
12.8
Describe the reaction of a group 1 element with water.
A vigorous reaction in which the metal floats and moves around the surface of the water fizzing.
12.9
Why do group 1 elements tarnish in the air?
Group 1 elements are very reactive with oxygen in the air and form a dull metal oxide layer on their surface.
12.10
Describe the reaction of a group 1 element with chlorine.
A very vigorous reaction.
13. Group 7
13.1
What is the name of elements in group 1?
The halogens.
13.2
Why do elements in group
7 have very similar properties?
They all have seven electrons in their outer shell.
13.3
Name two properties of group 7 elements.
• Non-metals.
• Consist of molecules made of
pairs of atoms.
13.4
When group 7 elements react with non-metals, what is formed?
Molecular compounds.
13.5
When group 7 elements react with metals, what is formed?
Salts.
13.6
Describe the trend in reactivity as you go down group 7.
Reactivity decreases.
13.7
What type of reaction would be occurring if a more reactive halogen reacted with the salt of a less reactive halogen?
A displacement reaction.
13.8
Describe the trend in melting and boiling point as you go down group 7.
Melting and boiling point increases.
13.9
Explain the trend in melting and boiling point as you go down group 7.
As you go down group 7:
• Molecular mass increases.
• Strength of attraction between
molecules increases.
• More energy is required to overcome
the forces of attraction.
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