With ethanol becoming more prevalent in the media and in gas tanks, it is important for students to know where it comes from. This module uses a series of four activities to show how energy and mass are converted from one form to another. It focuses on the conversion of light energy into chemical energy via photosynthesis, then goes on to show how the chemical energy in plant sugars can be fermented to produce ethanol. Finally, the reasons for using ethanol as a fuel are discussed.

This module follows the path of energy from the sun and photosynthesis to ethanol production. Teachers can stress that in every step of the process, energy is neither created nor destroyed; it just changes form. The same can be said of mass. The activities are:

• Plant pigment chromatography
• Plant mass
• Stored chemical energy

Handouts included. Eye protection, 1-, 2-, and 3-liter bottles, plant seeds (radish, spinach, bean, etc.), centigram balance, dried soil, pots, water, and a light source.

National Standards: 5-8

• INT-A: 1.a. Identify questions that can be answered through scientific inquiry.
• INT-A: 1.b. Design and conduct a scientific investigation.
• INT-B: 1.a. A substance has characteristic properties, such as density, boiling point, and solubility, all of which are independent of the amount of the substance.
• INT-B: 1.b. A mixture of substances can often be separated into the original substances using one or more of the characteristic properties.
• INT-C: 4.a. For ecosystems, the major source of energy is sunlight. Energy entering ecosystems as sunlight is transferred by producers into chemical energy through photosynthesis. The energy then passes from organism to organism in food webs.
• INT-F: 5.c. Technology influences society through its products and processes. Technological changes are often accompanied by social, political, and economic changes that can be beneficial or detrimental to individuals and to society. Social needs, attitudes, and values influence the direction of technological development.