General Knowledge Questions and Answers on Ozone Day

World Ozone Day is an important occasion that is observed to help protect the ozone layer and remind us about the roles that it plays in keeping the earth safe. The ozone layer is known as a protective layer that stops the harmful rays of the sun from reaching the earth directly. 

That is why people around the world come together to learn about this invisible shield, the dangers it faces, and the global efforts being made to save it.

This quiz has been designed to help you explore interesting facts about the ozone layer, its importance, and the global steps taken to protect it. You may already know some of the answers, while others might surprise you and give you new knowledge about how nature and science work together.

1. When is World Ozone Day observed every year?

a) 5 June

b) 16 September

c) 22 April

d) 11 July

Answer: b) 16 September

Explanation: World Ozone Day is observed on 16 September every year.

2. What is the theme for World Ozone Day 2025? 

a)  Restoring the Ozone Layer

b) Global Cooperation to Save Ozone

c) From Science to Global Action

d) Ozon for Life 

Answer: c) From Science to Global Action

Explanation: Every year there is a dedicated theme to celebrate the World Ozone Day and for the year 2025, the theme chosen is From Science to Global Action which urges people to take mindful actiosn to protect the ozone layer. 

3. Which gas is known as the main culprit to deplete ozone layer? 

a) Oxygen

b) Carbon dioxide

c) Methane 

d) Chlorofluorocarbons (CFCs)

Answer: d) Chlorofluorocarbons (CFCs)

Explanation: CFCs used in refrigerants and aerosols are the main cause of ozone depletion as they release chlorine atoms that destroy ozone molecules.

4. In which year the Montreal Protocol was signed? 

a) 1985

b) 2000

c) 1992

d) 1987

Answer: d) 1987

Explanation: The Montreal Protocol was signed on 16 September 1987. The UN Environment Programme mentions: "The Montreal Protocol on Substances that Deplete the Ozone Layer is a global agreement to protect the Earth’s ozone layer by phasing out the chemicals that deplete it. This phase-out plan includes both the production and consumption of ozone-depleting substances. The landmark agreement was signed in 1987 and entered into force in 1989."

5. Which layer of the Earth contains the ozone layer?

a) Troposphere

b) Stratosphere

c) Mesosphere

d) Exosphere

Answer: b) Stratosphere

Explanation: The ozone layer is located in the stratosphere, roughly 15 to 30 kilometres above the Earth’s surface. The US Environmental Protection Agency website mentions: "Most atmospheric ozone is concentrated in a layer in the stratosphere, about 9 to 18 miles (15 to 30 km) above the Earth's surface"

6. What does the ozone layer mainly protect us from?

a) Ultraviolet radiation

b) Acid rain

c) Earthquakes

d) Greenhouse gases

Answer: a) Ultraviolet radiation

Explanation: The ozone layer absorbs most of the harmful ultraviolet rays from the sun. The US Environmental Protection Agency states: "The ozone layer in the stratosphere absorbs a portion of the radiation from the sun, preventing it from reaching the planet's surface. Most importantly, it absorbs the portion of UV light called UVB. UVB has been linked to many harmful effects, including skin cancers, cataracts, and harm to some crops and marine life."

7. Where was the largest ozone hole first discovered?

a) North Pole

b) South Pole (Antarctica)

c) Himalayas

d) Sahara Desert

Answer: b) South Pole (Antarctica)

Explanation: Scientists discovered the ozone hole over Antarctica in the 1980s. 

8. Which international organization declared 16 September as World Ozone Day?

a) United Nations General Assembly

b) World Health Organization

c) World Meteorological Organization

d) Greenpeace

Answer: a) United Nations General Assembly

Explanation: The UN General Assembly declared 16 September as International Day for the Preservation of the Ozone Layer in 1994. The UN mentions: "In 1994, the United Nations General Assembly proclaimed 16 September the International Day for the Preservation of the Ozone Layer, commemorating the date of the signing, in 1987, of the Montreal Protocol on Substances that Deplete the Ozone Layer"

9. What is the chemical symbol for ozone?

a) O₂

b) O

c) CO₂

d) O₃

Answer: d) O₃

Explanation: Ozone is a molecule made up of three oxygen atoms, represented by the chemical symbol O₃.

10. Which of the following is a substitute for CFCs?

a) Hydrochlorofluorocarbons (HCFCs)

b) Hydrofluorocarbons (HFCs)

c) Both a and b

d) Carbon monoxide

Answer: c) Both a and b

Explanation: HCFCs and HFCs are commonly used as alternatives to CFCs, though some still have environmental impacts.