ONE-EIGHTH STAGE 2026
ROUND 5 - RIDDLE
RIDDLE
Aburi Girl’s SHS - 38 points
St. Joseph’s Seminary SHS - 20 points
Fafraha Community SHS - 12 points
St. John's Grammar School - 40
Mpraeso SHS - 23
Tema Secondary School – 13
St. Augustine’s College
Anlo SHS
Kumasi High School
RIDDLE
I'm a product of atmospheric chemistry.
I fall from the sky, yet I was never meant to be there.
I form when sulfur dioxide and nitrogen oxides are transformed into acid in the atmosphere.
Who am I?
ANSWER: Acid rain
EXPLANATION:
Acid rain forms when sulfur dioxide and nitrogen oxides are oxidised in the atmosphere and dissolve in rainwater, giving sulfuric and nitric acids that fall to the ground.
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PRACTICE QUESTIONS
1. RIDDLE:
I am an allotrope of oxygen.
Each of my molecules has three atoms.
I smell sharp after a thunderstorm.
High above you, I absorb harmful ultraviolet rays.
Chlorine atoms from CFCs destroy me in the stratosphere.
Near the ground, I am a pollutant in smog.
Who am I?
ANSWER: OZONE
EXPLANATION:
Ozone, $O_3$, shields the Earth from UV radiation in the stratosphere but is a harmful pollutant at ground level.
2. RIDDLE:
I am a warming process.
I trap heat near the Earth's surface.
Carbon dioxide, methane and water vapour drive me.
Without me the Earth would be about 33°C colder.
I work by absorbing infrared radiation given off by the ground.
Too much of me leads to global warming.
Who am I?
ANSWER: GREENHOUSE EFFECT
EXPLANATION:
Greenhouse gases absorb and re-emit infrared radiation, keeping the surface warmer than it would otherwise be.
3. RIDDLE:
I am a brownish haze over busy cities.
Sunlight is needed to make me.
Nitrogen oxides and hydrocarbons from car exhausts are my raw materials.
Ground-level ozone is one of my products.
I irritate the eyes and lungs.
Los Angeles was famous for me.
Who am I?
ANSWER: PHOTOCHEMICAL SMOG
EXPLANATION:
Photochemical smog forms when sunlight drives reactions between nitrogen oxides and hydrocarbons, producing ozone and other irritants.
4. RIDDLE:
I am a rise in the Earth's average temperature.
Extra greenhouse gases in the air drive me.
I melt glaciers and polar ice.
I raise sea levels.
Burning fossil fuels speeds me up.
The Paris Agreement aims to limit me to 1.5°C.
Who am I?
ANSWER: GLOBAL WARMING
EXPLANATION:
Global warming is the rise in average surface temperature caused by an enhanced greenhouse effect.
5. RIDDLE:
I happen in lakes and slow rivers.
Fertiliser run-off starts me.
Nitrates and phosphates feed me.
Algae bloom and cover the water surface.
Decomposers use up the dissolved oxygen during me.
Fish die from lack of oxygen because of me.
Who am I?
ANSWER: EUTROPHICATION
EXPLANATION:
Eutrophication is the over-enrichment of water with nutrients, leading to algal blooms and oxygen depletion.
6. RIDDLE:
I am the clearing of trees on a large scale.
Logging, farming and mining cause me.
I leave the soil open to erosion.
I reduce the uptake of carbon dioxide from the air.
I destroy the homes of many animals.
Planting trees reverses me.
Who am I?
ANSWER: DEFORESTATION
EXPLANATION:
Deforestation removes the trees that hold soil and absorb carbon dioxide.