1. Have students look at the periodic table and find the elements that are most common in living organisms. Ask them to determine how many electrons are in the outer shell of some common elements by looking at the atomic numbers.
2. Discuss how carbon14 breaks down into nitrogen14 and what the differences in protons and neutrons would be between these elements. Discuss how some isotopes are radioactive and others are not.
3. Discuss the formation of ions and how electrons are lost or gained in such formation. Make sure students understand that an ion can be a combination of atoms, and that even large molecules may become ionized at different locations within the molecule.
4. Consider the protons and electrons of an atom as the equivalent of the ends of a bar magnet, with positive and negative charges attracting each other, and electrons at greater distances from the nucleus having more energy because they are not as closely attracted to the positive charges of the protons.
5. Discuss how the pH system is logarithmic and how
each higher or lower unit is a ten-fold increase or decrease in
hydrogen ions.