Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum

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Science in Focus: Force and Motion
About the Workshops
1. Making an Impact
2. Drag Races
3. When Rubber Meets the Road
5. Keep on Rolling
6. Force Against Force
7. The Lure of Magnetism
Supplemental Resource List

Workshop 6 Web Highlights

"Protons, Neutrons, and Electrons"

All pure substances are composed of atoms. The center of an atom is composed of much smaller parts called protons, which have a positive electrical charge, and neutrons that have no charge. The protons and neutrons bind together in the nucleus. Surrounding the nucleus are even smaller parts called electrons, which have a negative electrical charge. Most atoms have about the same number of protons, neutrons, and electrons.



If we exert a force to pull a heavy object across the floor, we use energy and do work. If we move the object faster, we do the same amount of work, but we use more power. Power is the rate at which a task is performed. We measure power in a familiar unit called the watt. A 1000-watt microwave oven will cook food more quickly than a 500-watt model. It also uses more electrical energy. Another familiar power unit is horsepower (HP). A 50-HP tractor can plow a field much faster than a single horse.


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