Unit 1 B.3, B.4, B.5

In “The Electrical Nature of Matter”, we learned about the relationship between chemical bonds and atoms.  While like charges repel, unlike charges attract.  Every electrically uncharged atom has an equal amount of protons (positively charged particles) and electrons (negatively charged particles).  Also, some atoms have one or more neutron, or electrically neutral particle.  Attractions between positive and negative charges by the particles hold atoms together.  In the most recent periodic table, an element’s atomic number determines its position on the table.  An element’s atomic number is the amount of protons present.  Although earlier periodic tables were organized by an element’s mass number, or the combined mass of the protons and neutrons in the nucleus, the neutron made it difficult to record massive atoms.  All atoms of a certain element have the same number of protons, but the number of neutrons varies from atom to atom.  Isotopes are atoms with the same amount of protons, but with a varying amount of neutrons.