2. » What is the name of this device? » Which scientist used this device?

3. » Cathode Ray tube » JJ Thomson

4. » What experiment did Millikan do and what was one of his conclusions? Oil Drop Experiment Determined the mass of an electron (1/2000 th the mass of H atom) Determined the charge on the electron (negative)

5. » What experiment did Rutherford do and describe it?

6. » Rutherford did the gold foil experiment » Bombarded a thin piece of gold foil with fast moving positively charged alpha particles » Expected the alpha particles to pass straight through. Most did, but 1 in 8000 were deflected back.

7. » Complete the table for the main subatomic particles. ParticleRelative Charge Mass Number Location in atom Proton+11nucleus Neutron01nucleus Electron0Outside nucleus

8. » State 3 observations that Rutherford made (what did he see) and 3 conclusions he made from those observations.

9. 1.Most of the alpha particles passed straight through the foil – atom is mostly empty space 2.1 in 8000 particles bounced back – atom has a very tiny, dense nucleus 3.Some alpha particles deflected – nucleus has a positive charge b/c positive alpha particles are repelled

10. » What does the atomic number represent? » The number of protons in the nucleus of each atom of that element

11. » What does the mass number represent? » The number of protons + neutrons in the nucleus

12. » Define isotope » Atoms of the same element that have different masses

13. » How do nuclides of the same element differ from each other (be specific)? » The have a different number of neutrons

14. » Write the nuclear symbol and hyphen notation for the nuclide that has 2 protons and 2 neutrons. » Helium-4 4 He 2

15. » Define atom » The smallest particle of an element that retains the chemical properties of that element

16. » What nuclide is used as the standard in the relative scale for atomic masses? » What is its assigned atomic mass? Carbon-12 12 amu

17. » What is the definition of the mole? The amount of particles equal to the number of atoms in exactly 12 g of Carbon-12

18. » How many particles are in one mole? 6.022x10 23

19. » What is the name given to the number of particles in one mole? Avogadro’s number

20. » Calculate the average atomic mass of argon to 2 decimal places give the following isotopes: » Argon-36 (35.97amu; 0.337%) » Argon-38 (37.96amu; 0.063%) » Argon-40 (39.96amu; 99.600%) 39.95 amu

21. » Naturally occurring boron is 80.20% boron-11 (11.01amu) and 19.80% of another isotope. The average atomic mass of boron is 10.81amu. What must the atomic mass of the second isotope be? 10.01 amu

22. » How many atoms are in 6.755 mol Pb? 4.068x10 24 atoms

23. » How many atoms are in 0.250 mol Si? 1.51x10 23 atoms

24. » What is the mass in grams of 3.011x10 23 atoms F? 9.499 g

25. » What is the mass in grams of 25 atoms W? 7.6x10 -21 g

26. » Determine the number of atoms in 1.50g K. 2.31x10 22 atoms

27. » Determine the number of atoms in 0.02550 g Pt. 7.872x10 19 atoms

28. » Write the nuclear symbol and hyphen notation for the nuclide that has 6 protons and 8 neutrons. » Carbon-14 14 C 6

29. » How many isotopes does hydrogen have? Describe them.

30. » Protium – 1 proton, 0 neutrons, 1 electron (most common) » Deuterium – 1 proton, 1 neutron, 1 electron » Tritium – 1 proton, 2 neutrons, 2 electron (radioactive)

31. » What forces holds the nuclear particles together in the nucleus? » Nuclear forces

32. » How did Dalton’s theory explain the law of conservation of mass? » Chemical reactions involve the rearrangement of atoms, but atoms are not subdivided, created or destroyed.

33. » How many protons, electrons, and neutrons are there in an atom of chlorine-37? » 17p + ; 17e - ; 20n 0

34. » How many protons, electrons, and neutrons are there in an atom of bromine-80? » 35p + ; 35e - ; 45n 0

35. » Write the hyphen notation for the element that contains 15 electrons and 15 neutrons. » Phosphorous-30

36. » What is an amu? » 1/12 the mass of a carbon-12 atom » Atomic mass unit

37. » What is the mass in grams of 3.50 mol of the element copper? » 222 g of Cu

38. » The atomic mass of Tungsten is 83.84amu. What is the molar mass of Tungsten? » 83.84 g/mol

39. » How many atoms are in 132.90543g of Cesium? » 6.022x10 23 atoms of Cs

40. » How many moles of calcium are in 5.00g of calcium? » 0.125 mol Ca

41. » How many atoms of lead are in 52.7g of lead? » 1.53x10 23 atoms of Pb

42. » How many neutrons does uranium 238 have? » 146 neutrons

43. » How many protons does osmium-190 have? » 76

44. » What is the name of the nuclide that has 22 protons and 25 neutrons? » Titanium-47

45. » Write the nuclear symbol for the isotope of sodium with mass 23 23 Na 11

46. » A student finds that 15.20g of nitrogen will react with 17.37g, 34.74g, or 43.43g of oxygen to form three different compounds. This is an example of which law? Law of Multiple Proportions

47. » State the 5 points of Dalton’s atomic theory 1.All matter is composed of atoms 2.Atoms of a given element are identical in size, mass, and other properties 3.Atoms cannot be subdivided, created, or destroyed 4.Atoms of different elements combine in simple whole-number ratios to form chemical compounds 5.In chemical reactions, atoms are combined, separated, or rearranged.

48. » Which aspects of Dalton’s atomic theory were incorrect? Atoms cannot be subdivided – we know atoms are made of protons, neutrons & electrons. Atoms of a given element are identical in size, mass… - we know isotopes exist

49. » Describe 4 properties of electrons that were determined based on the experiments of Thomson and Millikan.

50. 1.Electron is negatively charged 2.Has a mass of 1/2000 th of H atom 3.Has a fixed charge to mass ratio 4.Present in atoms of all elements