Front

What happens when excess nutrients enter waterways?

Back

Algal blooms increase.

Front

What is true about smog?

Back

Smog is air pollution from burning fossil fuels and can look like a yellow haze over a city.

Front

What percentage of Earth's water is salt water?

Back

About 97%.

Front

What is the primary cause of most water pollution?

Back

Human activities.

Front

Which element is crucial for farming systems?

Back

Carbon.

Front

What is pollution?

Back

The introduction of harmful substances or products into the environment.

Front

What are algal blooms?

Back

Rapid increases in the population of algae in water bodies, often due to excess nutrients.

Front

What is the ozone layer?

Back

A region of Earth's stratosphere that absorbs most of the Sun's harmful ultraviolet radiation.

Front

What are fossil fuels?

Back

Natural substances formed from the remains of ancient plants and animals, used as energy sources.

Front

What is smog?

Back

A type of air pollution that is a mixture of smoke and fog, often seen in urban areas.