Name ________________________________________ Atoms Study Guide 1. Most of the mass of an atom is found in the ____nucleus______. 2. The atomic number is equal to the number of ________protons________ 3. The number of protons is equal to the number of ____electrons__________ 4. The ____atomic mass____________ is equal to the number of protons plus the number of neutrons. 4. The _______protons__________ and __________neutrons_________ are found in the nucleus. 5. Write each part of the atom and the charge for each part. Protons – positive charge Neutrons – neutral or no charge Electrons - negative charge 6. A pure substance made of only one kind of atom is called an __element_____ 7. Can two different elements (gold and silver) have the same atom? YES NO 8. What makes one element different from another? The number of protons is different for each element 9. If an element’s atomic number is 9 and atomic mass is 19, how many protons does it have? ___9____ 10. Complete the chart: Element Element Name Symbol Silver Ag Magnesium Mg Sulfur S Mercury Hg Plutonium Pu Atomic Number 47 12 16 80 94 Atomic Mass 108 24 32 201 244 # of protons 47 12 16 80 94 # of neutrons 61 12 16 121 150 # of electrons 47 12 16 80 94 (for the quiz, there will be different elements, but there will be a chart like this) 11. Identify this atom: __magnesium______ 12. Draw a model of a chlorine atom. Include the protons, neutrons, and electrons 17 electrons 17 protons 18 neutrons 13. Why are there an equal number of protons and electrons in an atom? To have the same number of positive and negative charges so that the atom is neutral. 14. What is the most common element that is found in the atmosphere, earth’s crust, human body, and ocean water? ____oxygen________________ 15. Circle the 6 elements that are most commonly found in the atmosphere, earth’s crust, human body, and/or ocean water. iron mercury hydrogen neon sodium carbon calcium nitrogen uranium helium