ozone

Everyday

1. A gas made of three oxygen atoms, which forms a layer high in the sky that protects Earth from harmful sunlight. tree →
2. A sharp smell, like after a thunderstorm or near the sea, that people often call ozone. tree →
3. (informal, old-fashioned) Fresh, clean air. tree →

In the lessons

In science lessons the ozone layer blocks much of the Sun's ultraviolet (UV) light; chemicals once used in sprays and fridges made a hole in it, and the world agreed to stop using them. Near the ground ozone is a pollutant that can hurt your lungs. In safety: wear sunscreen because UV light can still reach you. Phrases: the ozone layer, a hole in the ozone layer, ozone-friendly.

Examples

• The ozone layer protects us from harmful UV rays. tree →
• Some old sprays damaged the ozone. tree →
• After the lightning, the air smelled of ozone. tree →
• Ozone is made of three oxygen atoms. tree →
• On hot smoggy days, ozone near the ground can make breathing hard. tree →
• The fridge was labelled ozone-friendly. tree →

Note

Uncountable: some ozone, not «an ozone». Formula O3, while ordinary oxygen we breathe is O2. The ozone hole is a different thing from global warming, though people often mix them up.