1.33. Scientific Modeling http://www.ck12.org
to understand than a real water molecule. In a real molecule, electrons spin around the nuclei at the center of the
atoms in a cloud, rather than in neat, circular orbits, as shown in the model. The atoms of a real water molecule also
contain even smaller particles than protons, neutrons, and electrons. For many purposes, however, it’s not necessary
to represent these more complex features of a real water molecule.
The diagram below shows another example of a simple model in physical science. This diagram is a model of an
electric circuit. It represents the main parts of the circuit with simple symbols. Horizontal lines with + and –signs
represent a battery. The parts labeled R 1 , R 2 , and R 3 are devices that use electricity provided by the battery. For
example, these parts might be a series of three light bulbs.
Q:In the electric circuit diagram, what do the black lines connecting the battery and electric devices represent?
A:The black lines represent electric wires. The wires are necessary to carry electric current from the battery to the
electric devices and back to the battery again.
Q:How is a circuit diagram simpler and easier to understand than an actual electric circuit?
A:A circuit diagram shows only the parts of the circuit that carry electric current, and it uses simple symbols to
represent them.
Summary
- A model is a representation of an object, system, or process that is simpler and easier to understand than the
real thing. - Examples of simple models in physical science include two-dimensional models of molecules and electric
circuits.
Vocabulary
- model: Representation of an object, system, or process.
Explore More
Follow the instructions at this URL to make a model of an atom.