GCSE Chemistry · Edexcel 1CH0 · Topic 6A
Group 1
Key points
- Group 1 metals (lithium, sodium, potassium) are soft, have low melting points and low densities.
- They react with water to form a metal hydroxide and hydrogen: 2Na + 2H₂O → 2NaOH + H₂. The solution is alkaline.
- Observations: lithium fizzes steadily; sodium melts into a ball and whizzes around; potassium ignites with a lilac flame.
- Reactivity increases down the group because the outer electron is further from the nucleus and more shielded, so it is lost more easily.
- Melting point decreases down the group.
- Use the trend to predict the reactions of rubidium and caesium (even more vigorous).
Topic notesPremium
The Group 1 elements are called the alkali metals because they react with water to make alkaline solutions. They are so reactive that they are stored under oil to keep air and water away, and their trend in reactivity is a classic example…
Unlock the full notes with Premium
Premium includes full topic notes, the paper generator, self-quizzes and progress tracking.
Practise this topicPremium
Premium members can generate an exam-style paper with a mark scheme, or take a quick quiz, on Group 1.