Observing and Understanding Transformation

The video explains chemical changes, using a matchstick as an example. When a match is struck, it undergoes a chemical change, resulting in a new substance. Other examples include iron rusting and bread burning. Chemical changes also occur in the human body.

What happens to the match tip when it is struck against the matchbox?

• It becomes larger and changes color.

• It melts and turns into liquid.

• It bursts into flame and changes chemically.

• It remains the same but gets hotter.

What is a chemical change?

• A change in the physical state of a substance.

• A transformation where a substance becomes a new and different substance.

• A temporary change in the appearance of a substance.

• A process where a substance is dissolved in water.

What happens to iron when it undergoes a chemical change?

• It becomes shiny and smooth.

• It turns into a substance called rust with an orange color.

• It melts and becomes liquid.

• It remains unchanged but gets heavier.

Which of the following is an example of a chemical change?

• Burning a piece of bread.

• Melting ice into water.

• Mixing sand and water.

• Breaking a glass window.

Where do chemical changes occur in the human body?

• In the brain only.

• Only in the stomach.

• Only in the muscles.

• Throughout the entire body.