Concept 7 of 8Foundation
Watch on YouTubeVideoFast vs slow changes
Fast changes: happen in seconds or less.
- Lightning
- Explosion
- Burning paper
- Breaking glass
Slow changes: take hours to years.
- Rusting
- Fruit ripening
- Tree growing
- Rock weathering
Speed depends on temperature, surface area, moisture, and the substances involved.
Example
A slice of apple browns in minutes (oxidation). A whole apple in a fridge lasts weeks. Same chemistry, different speed.
💡 Tip:Heat generally speeds up chemical changes. Cold slows them (fridges preserve food).
▶Prefer a video? Open YouTube search for “fast slow changes class 6”↗