Plant seeds and watch them grow

What you'll need:

• Fresh seeds of your choice such as pumpkins seeds, sunflower seeds, lima beans or pinto beans.
• Good quality soil (loose, aerated, lots of peat moss), if you don’t have any you can buy some potting soil at your local garden store.
• A container to hold the soil and your seeds.
• Water.
• Light and heat.

Instructions:

1. Fill the container with soil.
2. Plant the seeds inside the soil.
3. Place the container somewhere warm, sunlight is good but try to avoid too much direct sunlight, a window sill is a good spot.
4. Keep the soil moist by watering it everyday (be careful not to use too much water).
5. Record your observations as the seeds germinate and seedlings begin to sprout from the seeds.

What's happening?

Hopefully after a week of looking after them, your seedlings will be on their way. Germination is the process of a plant emerging from a seed and beginning to grow. For seedlings to grow properly from a seed they need the right conditions. Water and oxygen are required for seeds to germinate. Many seeds germinate at a temperature just above normal room temperature but others respond better to warmer temperatures, cooler temperatures or even changes in temperature. While light can be an important trigger for germination, some seeds actually need darkness to germinate, if you buy seeds it should mention the requirements for that specific type of seed in the instructions.

Continue to look after your seedlings and monitor their growth. For further experiments you could compare the growth rates of different types of seeds or the effect of different conditions on their growth.

Melting Chocolate

What you'll need:

• Small chocolate pieces of the same size (chocolate bar squares or chocolate chips are a good idea)
• Paper plates
• Pen and paper to record your results

Instructions:

1. Put one piece of chocolate on a paper plate and put it outside in the shade.
2. Record how long it took for the chocolate to melt or if it wasn't hot enough to melt then record how soft it was after 10 minutes.
3. Repeat the process with a piece of chocolate on a plate that you put outside in the sun. Record your results in the same way.
4. Find more interesting locations to test how long it takes for the chocolate pieces to melt. You could try your school bag, hot water or even your own mouth.
5. Compare your results, in what conditions did the chocolate melt? You might also like to record the temperatures of the locations you used using a thermometer so you can think about what temperature chocolate melts at.

What's happening?

At a certain temperature your chocolate pieces undergo a physical change, from a solid to a liquid (or somewhere in between). On a hot day, sunlight is usually enough to melt chocolate, something you might have unfortunately already experienced. You can also reverse the process by putting the melted chocolate into a fridge or freezer where it will go from a liquid back to a solid. The chocolate probably melted quite fast if you tried putting a piece in your mouth, what does this tell you about the temperature of your body? For further testing and experiments you could compare white choclate and dark chocolate, do they melt at the same temperature? How about putting a sheet of aluminium foil between a paper plate and a piece of chocolate in the sun, what happens then?

Steel Wool & Vinegar Chemical Reaction

What you'll need: Steel Wool Vinegar Two beakers Paper or a lid (something to cover the beaker to keep the heat in) Thermometer Instructions: Place the steel wool in a beaker. Pour vinegar on to the steel wool and allow it to soak in the vinegar for around one minute. Remove the steel wool and drain any excess vinegar. Wrap the steel wool around the base of the thermometer and place them both in the second beaker. Cover the beaker with paper or a lid to keep the heat in (make sure you can still read the temperature on the thermometer, having a small hole in the paper or lid for the thermometer to go through is a good idea). Check the initial temperature and then monitor it for around five minutes. What's happening? The temperature inside the beaker should gradually rise, you might even notice the beaker getting foggy. When you soak the steel wool in vinegar it removes the protective coating of the steel wool and allows the iron in the steel to rust. Rusting (or oxidation) is a chemical reaction between iron and oxygen, this chemical reaction creates heat energy which increases the temperature inside the beaker. This experiment is an example of an exothermic reaction, a chemical reaction that releases energy in the form of heat.