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Introduction to Matter (Book)

Types of Matter

Elements and Atoms

The smallest particle of an element that still has the element’s properties is an atom. All the atoms of an element are alike, and they are different from the atoms of all other elements. For example, atoms of gold are the same whether they are found in a gold nugget or a gold ring (see Figure below). All gold atoms have the same structure and properties.

Gold is gold no matter where it is found because all gold atoms are alike.

PhET Activity

Build an Atom

from http://phet.colorado.edu/en/simulation/build-an-atom

Click on image to build an atom out of protons, neutrons, and electrons, and see how the element, charge, and mass change. Then play a game to test your ideas!

  • Use the number of protons, neutrons, and electrons to draw a model of the atom, identify the element, and determine the mass and charge.
  • Predict how addition or subtraction of a proton, neutron, or electron will change the element, the charge, and the mass.
  • Use the element name, mass, and charge to determine the number of protons, neutrons, and electrons.
  • Define proton, neutron, electron, atom, and ion.