Across
- 3. Antoine Lavoisier identified __________ as a mixture of oxygen and another gas.
- 5. Dalton's atomic model states that each ___________ is characterized by the mass of its atoms.
- 6. Thomson’s atomic model states that electrons have a _________ mass and a negative charge.
- 11. 1650 – Robert Boyle believed the four element model could be improved. He defined element as “certain simple _______________ bodies”.
- 13. Henry ____________ discovered that his gas would burn in oxygen and produce water.
- 16. Rutherford’s Atomic Model states that rapidly moving negatively charged electrons are scattered __________ the nucleus.
- 17. 1831 – Michael Faraday found that electric current could cause _____________ changes to some compounds.
- 18. A.D. 500-1600 – The _______________ devised chemical symbols for substances (now elements and compounds).
- 20. 350 B.C. – Aristotle also believed in the ________ element model and it influenced scientific thinking for almost 2000 years.
- 21. 450 B.C. – Greek scholar Empedocles proposed that matter was composed of four elements: earth, air, fire,___________.
- 22. Robert ____________ recognized that elements could be combined to form compounds.
- 25. Ernest Rutherford made the “nuclear” model and discovered the existence of a dense, positively charged core in the atom called the ____________.
- 27. In 400 B.C., ________________ suggested that matter was made of tiny particles called atoms that could not be broken down further.
- 31. Bohr’s atomic model states that the __________ of filling the first three orbits with electrons is 2, 8, and 8.
- 32. Michael _____________ believed that atoms could gain electric charges and form ions.
- 34. electrons have a negative charge and the rest of the atom is a sphere of ___________ charge.
- 35. Rutherford’s Atomic Model states that the nucleus is a very tiny, __________ and positively charged core of an atom.
Down
- 1. Bohr’s atomic model states that electrons move around the nucleus in circular paths called _________, like the planets circle the Sun.
- 2. Dalton’s model of the atom was called the “_____________ Ball” Model
- 4. Bohr’s atomic model states that each electron in an orbit has a definite amount of __________.
- 7. Bohr’s atomic model states that electrons cannot exist between these orbits, but can move up or down from one orbit to another if ____________ by heat, light or electrical energy.
- 8. J.J. Thomson formed the “__________ bun” model where the atom is a sphere of positive electricity with negative electrons imbedded in the positive sphere.
- 9. 1808 – John Dalton proposed that the atom is a solid, _______________, indestructible sphere and the atom contains no subatomic particles.
- 10. Niels Bohr made the “_______________” model by placing electrons in specific orbits around the nucleus.
- 12. Dalton's atomic model states that atoms are not ____________ or destroyed in a chemical change.
- 14. 1904 – J.J. Thomson discovered very light negative particles called _____________.
- 15. Bohr’s atomic model states that electrons are more ____________ when they are closer to the nucleus.
- 16. Late 1700’s – Joseph Priestly was the first person to isolate ____________.
- 19. Dalton's atomic model states that joining atoms of two or more elements forms _____________.
- 23. Bohr’s atomic model states that each orbit (energy level) is located at a certain _____________ from the nucleus.
- 24. Rutherford’s Atomic Model states that the nucleus is surrounded by mostly ___________ space.
- 26. Antoine Lavoisier defined element as a pure substance that ____________ be broken down into simpler substances. He discovered and identified 23 elements.
- 28. Rutherford’s Atomic Model states that all of the atom’s positively charged particles called ___________ are contained in the nucleus.
- 29. Bohr’s atomic model states that further the electron is from the nucleus, the ___________ its energy.
- 30. Dalton believed that atoms of the same element are exactly alike and have the same _________.
- 33. Henry Cavendish experimented by mixing metal with ________ which produced a flammable gas (hydrogen).