Day 1: Energy

Activity 1: Electrolysis and Electroplating

Using a Battery to Perform Electrolysis on Water. When current is passed through electrodes placed in water, the water is converted to hydrogen and oxygen gases. In this activity, a 9V battery is attached to two pencils and the graphite acts as the electrodes. Bubbles form at both electrodes and when phenophthalein and potassium iodide is added, around one electrode, the solution becomes basic (pink) and at the other electrode, iodide is turned into iodine (yellow).

What happens when you place a copper penny in silver nitrate solution? The copper metal atoms from the penny become copper ions and dissolve in the solution while the silver ions from the solution become silver metal atoms. Look at the picture and video below.

The penny becomes coated with small crystals of silver metal.

The silver metal on the penny will flake off very easily, but if you use a silver plating cream, you can perform the same process, but make the silver metal coat the copper and create a "silver penny". Look at the video and picture below.

A "Silver Penny"

When you place a nickel in copper solution, nothing happens. In this case energy is required to make the copper ions become copper atoms. If you attach a battery to the nickel and provide energy, you can coat a nickel with copper. Look at the video and picture below.

The nickel becomes coated with copper metal, making it look like a penny.

Activity 2: Electrochemistry

Can you make a battery out of a piece of fruit or vegetable? You can if you insert two pieces of different metals into the fruit. Watch the video below.

Which metals and fruits/vegetables worked the best? Check out the data below.

Click Here to Enlarge

Activity 3: Fuel Cells

A hydrogen-oxygen fuel cell creates electricity from hydrogen and oxygen gases and the only product it produces is water. Where do the hydrogen and oxygen come from? Electrolysis, which you performed in activity 1. Watch a demonstration of a simple fuel cell and one that is used to power a toy car below.

A Toy Fuel Cell Car

Activity 4: Solar Cells

Solar cells that convert light to electrical energy are all around us and used in calculators, watches, cell phone chargers, flashlights, radios, etc. How does the amount of electricity produced vary with the amount of light the solar cell receives? Watch the video below.

Activity 5: UV Color-Changing Beads

Light has different energy depending upon its color or wavelength. The sun emits very energetic ultraviolet (UV) light that can cause sunburn if we don't wear sunscreen. We can use UV-changing beads to test if sunscreen will absorb (and protect us from) UV light. What happens when you make a bracelet out of these beads and wear it in the sunlight? Watch the videos below.

Activity 7: Wind Power

Have you ever seen a wind turbine? When the wind forces the blades to move, it turns a generator that can create electricity. Can we make a small wind generator and determine how much energy it generates? Its not as easy as you might think. Watch the video below.

A Simple Wind Turbine

Activity 8: Burning Calories; The Energy in Food

The food that we eat provides us with chemical energy to live. Different foods contain different amounts of chemical energy, which we measure in units called Calories. How do you measure the number of calories in a piece of food? You burn (or combust) the food, where it reacts with oxygen an you measure the amount of energy (as heat) that is produced by having the reaction heat a known amount of water. From the temperature difference in the water (before and after combustion), you can calculate how many calories were produced by burning the food. Watch the video below.