Across
- 1. Came up with the "Atomic Theory of Matter"
- 6. Discovered neutrons
- 8. Discovered the electron
- 9. Father of the periodic table
- 11. substance that is made up of only one kind of atom
- 13. smallest part of an element that can be identified as that element and has properties of that element
- 15. Discovered that electrons go around the nucleus in different energy levels
- 18. when atoms of the same element have varying numbers of neutrons
- 19. characteristic used to describe an object
- 20. Occupy the top right hand corner of the periodic table; brittle, dull, mostly solids and gases at room temp, higher numbers of valence electrons
- 23. a column in the periodic table
- 24. anything that has mass and takes up space
- 25. number, the number of protons and neutrons added together
Down
- 2. particle that has no charge - located in the nucleus of an atom
- 3. center, or core, of an atom (where the protons and neutrons are located)
- 4. particle that has a positive charge - located in the nucleus of an atom.
- 5. a row in the periodic table
- 7. Realized that electrons are found in electron clouds
- 10. particle that has a negative charge - located in rings outside the nucleus of an atom.
- 12. , The largest portion of the elements on the periodic table; shiny, malleable, ductile, rust, lower number of valence electrons, almost all solids at room temp
- 14. Discovered the nucleus, protons, and said that atoms are mostly empty space
- 16. Ancient Greek who first proposed the idea of an atom
- 17. Cross between a metal and a nonmetal
- 21. atomic mass unit
- 22. mass, the weighted average of the nucleus of an atom