Introduction
    For living organisms, the most important liquid on Earth is water. It can also be found in a solid state as ice, and in the atmosphere as water vapor - a gaseous phases. Water has a number of properties that make it extremely versatile. We will explore a few of these.

Background
Temperature is a measure of the average kinetic energy of the particles in a substance. If energy is transfered from one substance to another the particles in the second substance speed up and thus the substance will have a higher temperature. How does this happen? In many ways. For example, putting a hot flame under a pot of water will transfer energy to the pot and then to the water which speeds up the water molecule movement (kinewtic energy increase) which can be measured as an increase intemperature with a thermometer. This transfer of energy is called heat. When energy moves from you into an object the object feels cool. If you can heat then you feel hot.
   The amount of heat it takes to raise the temperature of a substance is called its specific heat. Water has a high specific heat which means it will absorb a lot of solar radiation without changing temperature much. Also, it takes a lot of heat to evaporate the water. On the other hand, alcohol has a much lower specific heat, so which would you want in your car radiator - water or whiskey? Remember, you want to transfer a lot of heat from the engine to the water.

 A calorie is the amount of heat, energy transfer, needed to raise one gram of water 1 degree Celsius. One thousand calories (kilocalorie - Kcal) will raise one Liter of water one degree celsius. The calories listed on food packages are actually Kcal. A gram of protein has about 4 Kcal and a gram of fat has about 9 Kcal. Alcohol has around 7 Kcal. Why do fried foods and beer make for obese people?

If you start with one Liter of room temperature water (about 22 ^oC) and bring it to a boil (100 ^oC), how many calories will that take?
 

1 Liter x(100 - 20)degrees x 1Kcal/degree/Liter  = 80 KCal

Transfer of Energy
   Energy can be transfered from one object to another in several ways:

Conduction is the transfer of energy through matter by direct contact of particles whereas radiation is the transfer of heat by waves. Convection is the transfer of energy by bulk movement in fluids (liquids and gases are both fluids). For example, hot air expanding and rising carrying energy with it. Also, water molecule rising as steam carrying energy with them.

    In any energy transfer the perentage of energy that is transfered to the second substance is called efficiency. In general which method of heating a pot of water do you think would be most efficient - gas (radiation) or electric (conduction)? What should the pot be made of for the most efficient transfer. Remember our fire project. The spindle needed to be made out of a material with a low heat transfer. In heating water do we want a pot wiht high or low heat transfer?

Criteria

Quiz

1. What is the difference between temperature and heat?
2. What is a calorie?
3. What are the different means of energy transfer?
4. Complete a calorie problem like above

Project
One my gas grill we will heat some river rocks over HIGH heat. You will place oneLiter of water in a stainless steel pot. Add the hot rocks one at a time until the water boils. If it boils you pass. Assuming 100% efficiency, how many calories were in the rocks from being on the grill. Which is most efficient - heating rocks on the grill or heating the pot of water on the grill?