1. element 44 = atomic # 44 44 protons 44 electrons 66. How many protons and electrons are contained in an atom of element 44?

2. mass number (p + n) 12 -atomic number (p) - 6 = # of neutrons6 n 67. A carbon atom has a mass number of 12 and an atomic number of 6. How many neutrons does it have?

3. protons 80 + neutrons + 120 = Mass number 200 68. An isotope of mercury has 80 protons and 120 neutrons. What is the mass number of the isotope?

4. 69. An isotope of xenon has an atomic number of 54 and contains 77 neutrons. What is the xenon isotope’s mass number? protons 54 + neutrons + 77 = Mass number 131

5. 18 protons 70. Is an atom has 18 electrons, how many protons does it have?

6. Element Cl Zr Atomic Number 17 40 Mass Number 35379092 Protons 17 40 Neutrons 18205052 Electrons 17 40

7. electrons protonsneutrons a) 132 55 Cs 55 55 77 b) 59 27 Co 27 27 32 c) 163 69 Tm 69 69 94 d) 70 30 Zn 30 30 40 73. How many electrons, protons, and neutrons are contained in each?

8. electrons protons neutrons a)Gallium -69 31 31 38 b) fluorine-239 9 14 c) titanium-4822 22 26 d) tantalum-18173 73 108 74. How many electrons, protons, and neutrons are contained in each?

9. Ga- 69 must be more abundant because the atomic mass of gallium is closer to the mass of Ga-69 than the mass of Ga-71 76. Ga, which has atomic mass of 69.723 amu, has two naturally occurring isotopes, ga-69 and Ga-71. Which isotope occurs in greater abundance? Explain.

10. 107.86 amu 77. Silver has two isotopes 107 47 Ag, which has a mass of 106.905 amu and a percent abundance of 52.00% and 109 47 Ag, which has a mass of 108.905 amu and a percent abundance of 48.00%. What is the atomic mass of silver? 106.905 x.5200 = 55.59 108.905 x.4800 = 52.27

11. 51.99 amu 78. Data for chromium’s four naturally occurring isotopes are provided in the table. Calculate the atomic mass (amu). IsotopePercent AbundanceMass (amu) Cr- 504.3549.946 Cr- 5283.7951.941 Cr- 539.5052.941 Cr- 542.3653.939 = 2.17 = 43.52 = 5.03 = 1.27