Different speeds
Metals differ in reactivity with oxygen.
Metals in the open
Potassium, iron, copper and gold are kept in the open.
Do all metals react with oxygen in the same way?
What this lesson covers
The idea
Metals react with oxygen at different rates: potassium and sodium catch fire in the open, iron filings burn only in a flame, hot copper only gets an oxide coating, and silver and gold never react even at high temperatures.
Metals in the open
Potassium, iron, copper and gold are kept in the open.
Do all metals react with oxygen in the same way?
- No, they differ a lot
- Yes, in exactly the same way
- None reacts with oxygen
Sort by behaviour
Tap the group each metal belongs to.
Different rates
Not all metals react with oxygen at the same rate. Potassium and sodium catch fire in the open, so they are kept immersed in kerosene oil to prevent accidental fires. Iron filings burn in a flame. Hot copper only gets a black coat. Silver and gold do not react with oxygen even at high temperatures.
Metals react with oxygen at different rates: potassium and sodium catch fire in the open, iron filings burn only in a flame, hot copper only gets an oxide coating, and silver and gold never react even at high temperatures.
Notes
Metals react with oxygen at different rates: K, Na catch fire in the open, iron filings burn in a flame, hot copper gets an oxide coat, silver and gold do not react.
Check yourself
Which two metals catch fire if kept in the open?
Why are potassium and sodium kept immersed in kerosene oil?
Hot copper in air becomes coated with ...
Which metals do not react with oxygen even at high temperatures?
- Potassium and sodium — correct. Yes!
- Silver and gold. Silver and gold do not react with oxygen even at high temperatures.
- Iron and copper. Iron filings burn only in a flame, and copper only gets a coating when hot.
- To make them shine. The book gives the reason as protection and preventing accidental fires.
- To protect them and prevent accidental fires — correct. Yes!
- To make them react faster. Keeping them in kerosene oil protects them; it does not make them react faster.
- a green layer of copper carbonate. Basic copper carbonate is the green coat copper gets in moist air over time, not from heating.
- a brown flaky layer of rust. Rust forms on iron, not copper.
- a black layer of copper(II) oxide — correct. Yes!
- Silver and gold — correct. Yes!
- Potassium and sodium. Potassium and sodium react so vigorously that they catch fire in the open.
- Iron and copper. Iron filings burn in a flame and hot copper gets a black coat, so they do react.