• Absolute Zero- the lowest possible temperature that can be reached
  (minus 273.15° Celcius or C).
• Body Temperature- in humans is 37°C and is kept constant
  (unless sick or suffering from hypothermia).
• Boiling Point of Water- water will boil when its temperature reaches 100°C or higher.
• Celsius Scale- a temperature scale that puts the feezing point of water at 0°C and the boiling point of water at 100°C.
• Conductor- a substance through which heat energy or electricity travels
  (i.e. metal wire).
• Conduction- the process by which heat energy travels through a material or from one material to another when both materials are touching each other.
• Convection- the process by which heat energy is transferred in gases or liquids (hot air rises because it is less dense than the surrounding air. Denser, cooler air flows in to replace it, pushing hot air away which causes the wind to blow).
• Fever- occurs when your body becomes warmer than 37°C because of an illness.
• Freezing Point of Water- water will freeze when its temperature falls to 0°C or lower.
• HOT Air (Forced Air) Heating System- cool air is heated in a furnace (most common is a natural gas furnace), blown through the house using hot air ducts to air registers usually located on the floor in each room. Cool return air is drawn back to the furnace using cold air registers and cool air ducts. Thus, a circular system is created.
• HOT Water or Steam Systems- hot water or steam is created in the furnace or boiler and is circulated through insulated pipes to radiators located in each room of the building. Steam heat is used mostly in large buildings like apartments or schools.
• Hypothermia- occurs when the body temperature drops below 35°C when exposed to extremely cold temperatures or when immersed in cold water. If the body temperature drops to 30-33°C, death can occur!
• Insulator- a material that prevents heat from passing through it.
• Radiation- the process by which energy such as light or heat is transferred from a heat source through space to an object.
• Reflect- to send something back again (i.e. heat or light waves).
• Refrigerant- the liquid that provides cooling in a refrigerator.
• Solar Energy- energy from the sun in the form of light and heat.
• Solid- a state of matter whereby an object maintains its shape and volume and its molecules vibrate but do not change position.
• Temperature- the coldness or hotness of a material or object. (Find the current temperature outside your door now!)
• Thermometer- an instrument used to measure temperature.
• Thermostat- an instrument used to keep a machine working at a constant temperature (i.e. the thermostat in your house keeps the furnace working at a fixed temperature and can be adjusted up or down).
• Vacuum- a space or area that has nothing in it at all (no solids, liquids or gases).

Return to Grade 2 Science