11 Radioactivity This lab will examine two of the radioactive processes experienced by the nucleus of the atom, alpha decay and beta decay. These processes can be understood in terms of the last two fundamental forces of nature, the strong nuclear force and the weak nuclear force. Because these processes occur at an exponential rate, this lab will also explore the ideas of exponential growth and exponential decay. Main Ideas Strong Nuclear Force Weak Nuclear Force Radioactivity Half-Life Alpha Decay Beta Decay Exponential Decay Supplies 100 - 125 blocks with one side painted black Bucket Periodic Table Computer Geiger Counter for demo Radioactive Sources for demo Cloud chamber for demo 11.1 The Atomic Nucleus The nucleus of the atom is made up of protons, which carry a positive charge, and neutrons, which are electrically neutral. Dierent elements can be distinguished by the number of protons in the nucleus, which is known as the atomic number. The atomic mass or mass number is determined by the total number of nucleons (protons and neutrons combined). According to the electric force law, protons exert a repulsive force on one another because they carry the same type of charge. Because neutrons are electrically neutral