Question
2.34
2.49 (B) Applications Calculate the number of protons, neutrons, and electrons in: 2.28 Calculate the number of protons, neutrons, and electrons in: Light, 2.29 An atom has nine protons, ten neutrons, and nine elec- trons. Write the symbol of the atom Founda 2.51 o An atom has nineteen protons, neutrons, and nine- 2.52 I teen electrons. Write the symbol of the atom 2.31 How many protons are in the nucleus of the isotope Rn-220? 2.53 I 32 How many neutrons are in the nucleus of the isotope Rn-220? 2.33 Selenium-80 is a naturally occurring isotope. It is found in over-the-counter supplements a. How many protons are found in one atom 2.54 T b. How many neutrons are found in one atom of selenium-80? 2.34 Iodine 131 is an isotope used in thyroid therapy. 2.55 a. How many protons are found in one atom of iodine-131? b. How many neutrons are found in one atom of iodine-131? 2.56 2.35 Write symbols for each isotope: a. Each atom contains one proton and zero neutrons. 2.57 b. Each atom contains six protons and eight neutrons. 2.36 Write symbols for each isotope: a. Each atom contains one proton and two neutrons. b. Each atom contains 92 protons and 146 neutrons. 2.37 The element copper has 2.59 two naturally occurring isotopes. 2.60 One has a mass of 62.93 amu and a natural abun- dance of 69.09%. A second isotope has a mass of 64.9278 Appli amu and a natural abundance of 30.91%. Calculate the 2.61 238 atomic mass of copper. two naturally occurring isotopes 2.62 The has of these has a mass of 6.0151 amu and a natural abun- dance of 7.49%. A second isotope has a mass of 7.0160 amu 2.63 and a natural abundance of 92.51%. Calculate the atomic 2.64 mass of lithium. 2.65 Development of Atomic Theory 2.66 ations
Explanation / Answer
2.27 a) Ba has 56 protons, 56 electrons and 136 - 56 = 80 neutrons.
b) Po has 84 protons, 84 electrons and 290 - 84 = 125 neutrons.
2.28 a) Cl has 17 protons, 17 electrons and 37 - 17 = 20 neutrons.
b) Na has 11 protons, 11 electrons and 23 - 11 = 12 neutrons.
c) Kr has 36 protons, 36 electrons and 84 - 36 = 48 neutrons.
2.29 Fluorine "F"
2.30 Potassium "K"
2.31Rn has 86 protons in the nucleus.
2.32 Rn has 220 - 86 = 134 neutrons in the nucleus.
2.33 a) Selenium-80 has 34 protons.
b) Selenium-80 has 80 - 34 = 46 neutrons.
2.34 a) Iodine-131 has 53 protons.
b) Iodine-131 has 131 - 53 = 78 neutrons.
2.35 a) 11H
b) 146C
2.36 a) 31H
b) 23892U
2.37 62.93 x 69.09/100 + 64.9278 x 30.91/100 = 63.54 uma
2.38 6.0151 x 7.49/100 + 7.0160 x 92.51/100 = 6.93 uma
