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,
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.