Science ObjectDigital resources are stored online in your NSTA Library.
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the first of three Science Objects in the Atomic Structure SciPack. It discusses the basics of atomic structure and how we know what we know about atoms. Atoms are made of a positive nucleus surrounded by negatively charged electrons. The nucleus is a tiny fraction of the volume of an atom but makes up almost all of its mass. The nucleus is composed of protons and neutrons, which have roughly the same mass but differ in that protons are positively charged while neutrons have no electric charge. Isotopes of the same element have the same number of protons (and therefore of electrons) but differ in the number of neutrons. The electric force between the nucleus and electrons holds the atom together.