Matter and Energy

 

Objectives: After completing the lesson, students will be able to:

  describe the particulate model of matter;

  use the particulate model of matter to explain what happens to ice when energy (heat) is added to or subtracted from it.

 

Key Question: "What causes a solid (ice) to change into a liquid (water)?"

 

Overview: This activity introduces students to the particulate model of matter. Through a process of discussion and debate, they develop an understanding of what they observed in the previous lesson, as energy (in the form of heat) was added to water ice and dry ice. They are  presented with a brief history of the development of the concept of the atom, and introduced to the concepts of atoms, molecules, and the particulate model of matter.

 

Time Required: 45 minutes (1 class session).

 

Materials:

for the class

  one overhead transparency of each of the following (from the Dry Ice  GEMS guide): "Atoms in History" (p. 45); "Molecular Diagram of a Solid" (p. 46); and, "Energy and Matter Questionnaire (p. 47)

  three petri dishes, filled with varying amounts of BBs or plastic beads (used to model how molecules might look in a solid, a liquid, and a gas)

  overhead projector

for each student

  one copy of the "Energy and Matter Questionnaire" (p. 47)

 

 

Procedure: see pp. 39-44 of the  Dry Ice  GEMS guide.

 

Assessment: "Energy and Matter Questionnaire".

 

Homework: review "Science Safety Rules" from the first lesson.

 

OUSD Science Content Standards (State of California Science Content Standards):  

1-f (7-e); also a useful introduction to concepts involving energy transfer,

which comprises OUSD standard 3 (State standard 3).

 

References:

Barber, Jacqueline, Kevin Beals, and Lincoln Bergman. Dry Ice Investigations: Teacher's Guide. Berkeley, CA.: Lawrence Hall of Science, University of California, Berkeley, 1999, pp. 37-47.

 

Notes:

            Every effort should be made to give students a chance to create their own explanations for their observations from the previous lesson. It is also important to review laboratory safety procedures and how they apply to working with dry ice at the end of this lesson. An emphasis on why it is necessary to handle dry ice as carefully as possible will help prevent problems in the next lesson.

 

Key Vocabulary:

energy: the capacity to do work.

 

heat: the energy that an object has because its molecules are moving.

 

particulate model of matter: all matter is made up of tiny, moving particles, called atoms. Atoms are too small to be seen with an ordinary microscope. Individual atoms combine to form molecules. There is space between molecules, and they are always moving. When heat is added to an object, the molecules that make up the object move faster and farther apart.