Oxygen from plants

The idea

Oxygen is released during photosynthesis, which occurs in the presence of sunlight.

Taking in, giving out

During photosynthesis a plant takes in carbon dioxide and water.

Does the plant also give out something?

• Yes, a gas
• Yes, a solid
• No, it gives out nothing

Water plant experiment

A water plant is kept under a funnel and an upside-down test tube full of water. Try the set-up in sunlight and in the dark.

Oxygen is released

In sunlight bubbles came out of the plant and gas collected in the test tube. The gas is rich in oxygen. In the dark nothing collected.

Oxygen is released during photosynthesis, which occurs in the presence of sunlight.

Notes

Oxygen is released during photosynthesis, which occurs in the presence of sunlight.

Check yourself

Which gas is released during photosynthesis?

In the experiment, where did the gas collect?

In which set-up did bubbles of gas appear?

What does this experiment show?

• Carbon dioxide. Carbon dioxide is taken in during photosynthesis.
• Oxygen — correct. Yes! The gas is rich in oxygen.
• Nitrogen. The gas released is oxygen.
• Inside the funnel only. The gas went up into the test tube, which is where it was collected.
• At the bottom of the beaker. The bubbles rose and the gas collected at the top of the test tube.
• At the top of the test tube — correct. Yes! The bubbles rose and collected there.
• The set-up in sunlight — correct. Yes! Photosynthesis occurs in sunlight.
• The set-up in the dark. In the dark no gas collected.
• Both set-ups, the same. Only the set-up in sunlight gave gas.
• Plants prepare food only in the dark. Gas was released in sunlight, not in the dark.
• Oxygen is released during photosynthesis, in sunlight — correct. Yes! That is what the experiment shows.
• Plants release carbon dioxide while making food. Carbon dioxide is taken in. The gas released is oxygen.