Question

1. give the symbol and number of neutrons in one atom of: (to get “mass number”, you must round the “atomic mass” to the nearest whole number) show your calculations. barium _____________ bismuth ___________ carbon ___________ hydrogen ___________ fluorine ___________ magnesium ___________ europium ___________ mercury _____________

Explanation:

Step1: Recall the atomic number and atomic mass information

We need to look up the atomic number (number of protons) and atomic mass of each element from the periodic - table. The mass number is obtained by rounding the atomic mass to the nearest whole number. The number of neutrons is calculated as mass number - atomic number.

Step2: Calculate for Barium (Ba)

Atomic number of Ba is 56. Atomic mass of Ba is approximately 137.33. Rounding the atomic mass, the mass number \(A = 137\). Number of neutrons \(n=A - Z=137 - 56 = 81\). Symbol: \(^{137}_{56}Ba\)

Step3: Calculate for Carbon (C)

Atomic number of C is 6. Atomic mass of C is approximately 12.01. Rounding the atomic mass, the mass number \(A = 12\). Number of neutrons \(n=A - Z=12 - 6 = 6\). Symbol: \(^{12}_{6}C\)

Step4: Calculate for Fluorine (F)

Atomic number of F is 9. Atomic mass of F is approximately 19.00. Rounding the atomic mass, the mass number \(A = 19\). Number of neutrons \(n=A - Z=19 - 9 = 10\). Symbol: \(^{19}_{9}F\)

Step5: Calculate for Europium (Eu)

Atomic number of Eu is 63. Atomic mass of Eu is approximately 151.96. Rounding the atomic mass, the mass number \(A = 152\). Number of neutrons \(n=A - Z=152 - 63 = 89\). Symbol: \(^{152}_{63}Eu\)

Step6: Calculate for Bismuth (Bi)

Atomic number of Bi is 83. Atomic mass of Bi is approximately 208.98. Rounding the atomic mass, the mass number \(A = 209\). Number of neutrons \(n=A - Z=209 - 83 = 126\). Symbol: \(^{209}_{83}Bi\)

Step7: Calculate for Hydrogen (H)

Atomic number of H is 1. Atomic mass of H is approximately 1.01. Rounding the atomic mass, the mass number \(A = 1\). Number of neutrons \(n=A - Z=1 - 1 = 0\). Symbol: \(^{1}_{1}H\)

Step8: Calculate for Magnesium (Mg)

Atomic number of Mg is 12. Atomic mass of Mg is approximately 24.31. Rounding the atomic mass, the mass number \(A = 24\). Number of neutrons \(n=A - Z=24 - 12 = 12\). Symbol: \(^{24}_{12}Mg\)

Step9: Calculate for Mercury (Hg)

Atomic number of Hg is 80. Atomic mass of Hg is approximately 200.59. Rounding the atomic mass, the mass number \(A = 201\). Number of neutrons \(n=A - Z=201 - 80 = 121\). Symbol: \(^{201}_{80}Hg\)

Answer:

Barium: Symbol \(^{137}_{56}Ba\), 81 neutrons
Carbon: Symbol \(^{12}_{6}C\), 6 neutrons
Fluorine: Symbol \(^{19}_{9}F\), 10 neutrons
Europium: Symbol \(^{152}_{63}Eu\), 89 neutrons
Bismuth: Symbol \(^{209}_{83}Bi\), 126 neutrons
Hydrogen: Symbol \(^{1}_{1}H\), 0 neutrons
Magnesium: Symbol \(^{24}_{12}Mg\), 12 neutrons
Mercury: Symbol \(^{201}_{80}Hg\), 121 neutrons