In the first unit, we looked at atoms in terms of the subatomic particles making up atoms – the nucleus, which is in the center of the atom and contains almost all of the mass. The nucleus is very, very tiny compared to the atom, so most of the atom is empty space. The electrons occupy that empty space, and as we will see, largely determine the behavior of the different elements.
We will start our study of electrons by looking at light and electromagnetic radiation, because electrons behave like light waves as much as they behave like little negative particles. Also, much of what we know about electrons came from observing the interaction of light with matter.
We will then examine studies and discoveries that began to link the information on radiation and waves to electrons and atoms before looking at the quantum-mechanical theory of electrons and how it describes the motion, location, and energy of electrons in atoms. We will close with a look at how the conclusions of electron behavior from quantum mechanics are connected with position on the periodic table and trends in element properties.
