Unit 2: Activity 1: What factors affect material changes
Substances may change due to external factors such as air, water, and temperature, some change quickly, some slower, and remain stable after long-term action.
The speed of change in matter is faster The phenomenon of change in matter is slower
For example, ice cubes turn into water, cut apples change color, chocolate becomes soft, wood burns, fresh milk spoils at room temperature, etc. For example, rocks change shape, blades or nails rust, old books or paper turn yellow, bicycles rust, etc.
Exposure to the sun, rubbing hands, using electric heaters, and starting fires can generate heat and raise the temperature.
In addition to physical sensations, using a thermometer can accurately determine temperature changes.
