The Atom

Atoms

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	4					5		6
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	9
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18
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											20	21
22
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Across 6. opposite charges ____ each other 7. number of protons in an atom 9. space surrounding the nucleus 11. positive charged particle 12. An atom with mass number 75 and 44 protons would have how many neutrons [spell out number] 13. discovered electrons 17. all the radiaoctive decays an element goes through to become stable 19. splitting a Uranium nucleus to release energy 20. decay that releases only energy; no particles 22. negative particle 23. atoms of the same element with different mass numbers 24. an electron form a nuclear decay is a ____ particle. 25. alpha radiation is easily stopped by this material

Down 1. ___ and ___ were the first two atomic bombs 2. joining 2 hydrogen nuclei to form a helium nucleus 3. like charges _____ each other 4. discovered the nucleus 5. used to control the rate of reaction in a nuclear power reactor 8. neutral particle 10. A particle of 2 protons and 2 neutrons 14. protons and neutrons combined 15. time required for 1/2 of a radioactive sample to decay 16. discovered radioactivity 18. small, dense and solid 21. smallest particle of matter that retains properties

The look has changed! Some of the puzzles that people list for the public get indexed by the search engines (like Google). Some people find those puzzles and cannot figure out how to make a puzzle of their own. So this page now has the navigation sidebar.

Use the "Printable HTML" button to get a clean page, in either HTML or PDF, that you can use your browser's print button to print. This page won't have buttons or ads, just your puzzle. The PDF format allows the web site to know how large a printer page is, and the fonts are scaled to fill the page. The PDF takes awhile to generate. Don't panic!