1. What is an isotope? _____________________________________________________________ ________________________________________________________________________________ 2. What does the number next to isotopes signify? _______________________________________ ________________________________________________________________________________ 3. How can you tell isotopes apart? ___________________________________________________ ________________________________________________________________________________ For each of the following isotopes, write the number of protons, neutrons, and electrons. Chromium-58 Chromium-63 # of protons # of protons # of neutrons # of neutrons # of electrons # of electrons Half-life of… Half-life of… Nitrogen-15 # of protons # of neutrons # of electrons Half-life of… Carbon-16 Sulfur-23 Sulfur-25 Selenium-30 Selenium-35 Nitrogen-20 7 7 8 13 7 7 stable 136ms Sodium-12 Carbon-12 # of protons # of neutrons # of electrons Half-life of… Sodium-20 # of protons # of protons # of neutrons # of neutrons # of electrons # of electrons Half-life of… Half-life of… Fill in the isotope names and any missing information, including isotope numbers from the chart. Use your periodic table and the information provided. # of protons # of protons 25 32 # of neutrons 17 # of neutrons 15 # of electrons # of electrons # of protons # of protons # of neutrons 30 32 113 111 # of neutrons 48 51 # of electrons # of electrons 46 Iron-___ 55 Iodine- Iron-___ # of protons # of protons # of neutrons # of neutrons 27 32 30 35 # of electrons # of electrons Germanium- Iodine- Germanium- -10 # of protons # of protons # of neutrons # of neutrons -12 6 33 36 # of electrons # of electrons 6 -22 # of protons -25 -54 # of protons 24 # of neutrons # of neutrons # of electrons # of electrons 11 -56