Science Project Ideas for Kids

The Sun and sky have such beautiful colors sometimes. It amazes me that they change because of such teeny tiny particles in Earth’s atmosphere.

The Sun gets so hot that it emits white light, which is a combination of all the visible colors of light. When this white light passes through Earth’s atmosphere some of the colors are scattered in different directions. The sky is blue because blue light is scattered in all directions. The sky is red in the photo because the red parts of the Sun’s white light is scattered. The light that is not scattered gives the Sun is color.

You can demonstrate the scattering of light using a flashlight, milk, and water.

Discover for Yourself

1. Fill a clear glass with water.

2. Set the glass on a surface where you can place a white screen. Use a wall for your screen if the wall is white. White poster board or white paper can make good screens.

3. In a darkened room, shine the light through the water and observe the color of the water as well as the colored spot on the white screen.

4. Add  one drop of milk to the water. Stir.

5. Shine the light through the milky. Again observe the color of the liquid in the glass as well as the color of the light spot on the screen.

6. Repeat steps 4 and 5 two or more times.

What’s Happening?

The fat particles in the milk, like particles in the atmosphere, scatter light. The colors scattered depend  on the size and amount of particles.

Astronomy for Every Kid: 101 Easy Experiment That Really Work

I need to make a correction and update the answer for this question. I incorrectly used the term phosphorescence for the glow of a scorpion–It is actually an example of fluorescence.

Question: Why do scorpions glow under a black light?

Answers:

The scorpion has phosphors in its exoskeleton.

1. A  phosphor is a term used to describe any substance that absorbs  a form of high-energy light and releases it in the form of lower energy light.

2. Black lights give off  Ultraviolet A, which is a type of high-energy. When the phosphor in the exoskeleton of a scorpion absorbs UVA, some of the electrons in the atoms making up the phosphor  become excited. This means that the electrons move further way from the nucleus. These excited electrons quickly release energy and return to their normal position, called ground state. The released energy is in the form of lower-energy visible light. Thus the scorpion glows as shown under a black light.

The glow from the scorpion is an example of photoluminescence. WOW! That is a big word, but it is actually easy and certainly fun to experiment with. Let’s take the word apart–photo is a prefix for light and luminescence is any cold light–light from something that is not hot. OK, if we put the word parts back together we have a cold light produced by some light source. This source excited electrons, and then they release visible light when they “calm down” or return to ground state.

The scorpion only glows during the time it is exposed to black light (UVA). This type of luminescence is called fluorescence.

Some things continue to glow after the light energy source is removed. This type of luminescence is called phosphorescence. These materials can store the absorbed light energy and release it slowly. Examples are glow-in-the dark toys. Also solar active materials, such as beads that change colors when exposed to sunlight or black light.

Bananas grow in bunches. Like other fruit, ethylene gas produced by ripening bananas speeds up the ripening process.

I read that leaving  bananas attached to their stem  speeds up their ripening process.  Is this really true? How could you find out?

This would make a great science project. Just make sure that all the bananas being tested are at the same stage of ripening. Also, since bananas connected to the stem touch each other, you would have to place separated bananas in a similar position.

For more information about fruit ripening, see Fruit Ripening.

The far side of the Moon is the side that never faces Earth, and it is not always dark. In fact, a little more than half of the Moon’s surface is lit all the time. From Earth, you can only see about half of the Moon’s surface and it is always the same. So how does the Moon orbit around Earth so that only one side faces Earth?

The answer to this questions may be easier to understand by doing a simple investigation. For details, see  MOON: MOVEMENTS