Chemical Vs. Physical Reactions for Kids
One might think that chemical reactions only happen in science labs, but they are actually happening every moment around us.
Every time we eat, our body uses chemical reactions to break down our food into energy.
Rusting of metal, burning of wood and photosynthesis in plants -all are perfect examples of chemical reactions.
Similarly, physical reactions keep happening around us every minute e.g. Melting of candle, dissolving something, boiling wate etc.
Difference between chemical and physical changes
In a chemical change or reaction, a new substance is made, like when you burn a candle Anytime a new substance is made, it is an example of a chemical change. Usually two or more materials combine and a new substance is formed.
A chemical change can involve explosions, like fireworks. But on the other hand, few chemical changes are a little more difficult to spot, like rusting of a nail. In a physical change or reaction, no new substance is made, like when water turns to ice.
A physical change can be a change in the shape or appearance of an object, like crumpling a piece of paper, or cutting, bending, or dissolving something.
The key point to note here is that since objects do not become a different substance during a physical change, it is usually easy to reverse the change.
For example, if you dissolve sugar in water you can easily reverse the change by evaporating the water from the solution. When all the water evaporates, sugar will be left behind.