32. Explain Rutherford’s Gold Foil experiment and what he discovered about the atom Since most of the alpha particles passed through the foil, atoms must be mostly empty space. Some of the positively charged particles bounced back showing that there was a small dense area of positive charge with mass in the center of the atom (the nucleus)
33. What part of a radioactive atom is unstable? A Unit 4 for 100
34. What part of a radioactive atom is unstable? The nucleus
35. The half life of radon-222 is 20 minutes. After how many minutes is there only 12.5% of the parent isotope left? A Unit 4 for 200
36. The half life of radon-222 is 20 minutes. After how many minutes is there only 12.5% of the parent isotope left? Amount Half life Time 100% 0 0 50% 1 20 min 25% 2 40 min 12.5% 3 60 min
37. What particle is emitted when cabon-14 decays into nitrogen-14? A Unit 4 for 300
38. What particle is emitted when cabon-14 decays into nitrogen-14? A beta particle C N + e
39. Which two types of decay produce the same product? A Unit 4 for 400
40. Which two types of decay produce the same product? Electron capture and positron emission C + e B C B + e
41. Describe the mass and atomic number of an alpha particle AND its penetrating power A Unit 4 for 500
42. Describe the mass and atomic number of an alpha particle AND its penetrating power Mass (protons + neutrons) = 4 Atomic Number (protons) = 2 Penetrating Power = low (too massive)
43. What is the charge on an atom in group 5? A Unit 5 for 100
44. What is the charge on an atom in group 5? An atom in group 5 has 5 valence electrons, it wants to gain 3 more. The charge will be -3
46. Give the electron configuration for Bromine Full: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 5 Noble Gas Shorthand: [Ar] 4s 2 3d 10 4p 5
47. What happens to atomic radius (size) moving down a group? WHY? A Unit 5 for 300
48. What happens to atomic radius (size) moving down a group? Down a group the radius increases because each new period requires the use of new orbitals (1s to 2s to 3s…etc)
49. What happens to the atomic radius (size) moving across a period to the right? WHY? A Unit 5 for 400
50. What happens to the atomic radius (size) moving across a period to the right? The size of an atoms gets smaller moving across a period because the number of protons increase, pulling the electrons in the orbital in tighter
51. Is the trend for ionization energy the same or the opposite of the trend for atomic radius? WHY? A Unit 5 for 500
52. Is the trend for ionization energy the same or the opposite of the trend for atomic radius? WHY? The trend for ionization energy is OPPOSITE ; as the size (radius) of the atom increases it is easier to remove an electron- therefore the energy required to form an ion is lower
