International Year of Chemistry: a workshop.

Josep's mum, Núria , is a chemist. She came to school and did lots of experiments to us: a battery with a lemon, small pieces of paper that showed if a liquid was acid or basic, liquids that changed colour when adding some drops of another liquid... We thought they were magic!

When she finished we asked her many questions.

WHAT DO YOU THINK ABOUT IT? WRITE YOUR COMMENTS!

International Year of Chemistry: no fire for a fried egg

MATERIALS:

- An egg.

- A plate or a bowl.

- Alcohol.

INSTRUCTIONS:

- Break the egg and put it in the plate.

- Pour some alcohol on it.

- Wait half an hour.

- It's a fried egg!

WHY?

Eggs contain proteins. When you heat proteins they undergo a structural change called denaturation. You can get the same result with alcohol. In this process the egg white becomes solid and white.

WHAT DO YOU THINK ABOUT IT? WRITE YOUR COMMENTS!

International Year of Chemistry: the balloon

MATERIALS:

- A bottle.

- A balloon.

- Vinegar.

- Sodium bicarbonate.

- A funnel.

INSTRUCTIONS:

- Fill half of the bottle with vinegar.

- Fill the balloon with sodium bicarbonate. Use the funnel.

- Adjust the balloon to the bottle.

- Pour the bicarbonate to the vinegar.

- The balloon starts to blow up.

WHY?

When bicarbonate mixes with vinegar (an acid) it produces carbon dioxide. This is the gas that blows the balloon up.

WHAT DO YOU THIN ABOUT IT? WRITE YOUR COMMENTS!

International Year of Chemistry: Physical or Chemical change?

MATERIALS:

- 2 plates - 2 sheets of paper - a lighter INSTRUCTIONS: - Make a ball with one of the sheets and place it on a plate. - Fold the second sheet of paper, place it on the plate and burn it. - The first sheet has suffered a physical change, and the second one a chemical change. WHY? The first sheet of paper is still paper, it keeps its properties. It has only changed its shape and size: it's a physical change. The second sheet of paper isn't paper any more. Now it's something different, it's ash: it's a chemical change. WHAT DO YOU THINK ABUOT IT? WRITE YOUR COMMENTS!