Unit 3 Atomic Theory

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Across
  1. 4. electron emitted during fission
  2. 7. atomic nucleus splits and releases lots of energy
  3. 9. An isotope of hydrogen with one proton and one neutron in the nucleus having a mass number of 2
  4. 10. The sum of protons and neutrons in an atom's nucleus
  5. 11. ray of energy emitted during fission
  6. 12. Number of protons; identifies the element
  7. 13. an isotope of hydrogen with one proton and two neutrons in the nucleus having a mass number of 3
  8. 16. force that holds the nucleus (protons and neutrons) together
  9. 18. A negatively charged ion
  10. 19. when elements change into different elements because the number of protons has changed
  11. 21. A charged atom created by gaining or losing electrons
  12. 22. A positively charged ion
  13. 23. Made up of protons and neutrons; Center of an atom
Down
  1. 1. The Nuclei of two atoms combine to create a new atom
  2. 2. Average mass of all the known isotopes of an element
  3. 3. positively charged subatomic particle; located in the nucleus; mass of 1 a.m.u
  4. 5. most common hydrogen isotope; has one proton and no neutrons so the mass number is 1
  5. 6. A pure substance made of only one kind of atom
  6. 8. # of protons - # of electrons
  7. 12. two protons and two neutrons (a helium ion) emitted during fission
  8. 14. Atoms of one element that have different numbers of neutrons
  9. 15. negatively charged subatomic particle; located in the electron cloud; mass of basically nothing
  10. 17. neutrally charged subatomic particle; located in the nucleus; mass of 1 a.m.u.
  11. 20. Basic unit of matter; Smallest particle of an element