Science Education Standards: Earth and Space Science -- Content Standard D

Properties and Changes of Properties in Matter

• A substance has characteristic properties, such as density, a boiling point and solubility, all of which are independent of the amount of the sample. A mixture of substances often can be separated into the original substances using one or more of the characteristic properties.

Earth in the Solar System:

• The Earth is the third planet from the sun in a system that includes the Moon, the sun, seven other planets and their moons, and smaller objects, such as asteroids and comets.

Structure of the Earth System:

• Water, which covers the majority of the Earth's surface, circulates through the crust, oceans, and atmosphere in what is known as the "water cycle." Water evaporates from the Earth's surface, rises and cools as it moves to higher elevations, condenses as rain or snow, and falls to the surface where it collects in lakes, oceans, soil, and in rocks underground.

• Water is a solvent. As it passes through the water cycle it dissolves minerals and gases and carries them to the oceans.

Short Description: This demonstration of the composition of a comet uses dry ice and several common ingredients to make a nucleus that will release jets of gas and sublimate over time.