The statue that dissolves
An old marble statue slowly loses its face — not to vandals but to acid rain, born when factory smoke mixes with clouds. Human activity can rewrite the chemistry of the very rain that falls miles away.
When rain turns acidic
Burning fossil fuels releases sulfur and nitrogen oxides that react with water to form acids, lowering the pH of rain. Acid rain damages forests, lakes, and buildings. The same combustion releases CO₂, a greenhouse gas that warms the planet.
Simulation · The pH scale
pH 7
pH 7 — neutral
Normal rain is slightly acidic (~5.6). Acid rain drops well below that — slide down toward pH 4 to see it.
Lab · Read the rain
- Set the pH slider to 7 (neutral).
- Move to about 5.6 — normal rainwater.
- Now drop to 4 — that's acid rain.
What you should see: Lower pH means more acidic; acid rain (≈pH 4) is far more acidic than normal rain.