Additional Exercises
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How many electrons does it take to make the mass of one proton?
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How many protons does it take to make the mass of a neutron?
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Dalton’s initial version of the modern atomic theory says that all atoms of the same element are the same. Is this actually correct? Why or why not?
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How are atoms of the same element the same? How are atoms of the same element different?
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Give complete atomic symbols for the three known isotopes of hydrogen.
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A rare isotope of helium has a single neutron in its nucleus. Write the complete atomic symbol of this isotope.
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Use its place on the periodic table to determine if indium, In, atomic number 49, is a metal or a nonmetal.
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Only a few atoms of astatine, At, atomic number 85, have been detected. On the basis of its position on the periodic table, would you expect it to be a metal or a nonmetal?
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Americium-241 is a crucial part of many smoke detectors. How many neutrons are present in its nucleus?
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Potassium-40 is a radioactive isotope of potassium that is present in the human body. How many neutrons are present in its nucleus?
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Determine the atomic mass of ruthenium from the given abundance and mass data.
Ruthenium-96 5.54% 95.907 u Ruthenium-98 1.87% 97.905 u Ruthenium-99 12.76% 98.906 u Ruthenium-100 12.60% 99.904 u Ruthenium-101 17.06% 100.906 u Ruthenium-102 31.55% 101.904 u Ruthenium-104 18.62% 103.905 u -
Determine the atomic mass of tellurium from the given abundance and mass data.
Tellurium-120 0.09% 119.904 u Tellurium-122 2.55% 121.903 u Tellurium-123 0.89% 122.904 u Tellurium-124 4.74% 123.903 u Tellurium-125 7.07% 124.904 u Tellurium-126 18.84% 125.903 u Tellurium-128 31.74% 127.904 u Tellurium-130 34.08% 129.906 u -
One atomic mass unit has a mass of 1.6605 × 10−24 g. What is the mass of one atom of sodium?
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One atomic mass unit has a mass of 1.6605 × 10−24 g. What is the mass of one atom of uranium?
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One atomic mass unit has a mass of 1.6605 × 10−24 g. What is the mass of one molecule of H2O?
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One atomic mass unit has a mass of 1.6605 × 10−24 g. What is the mass of one molecule of PF5?
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From their positions on the periodic table, will Cu and I form a molecular compound or an ionic compound?
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From their positions on the periodic table, will N and S form a molecular compound or an ionic compound?
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Mercury is an unusual element in that when it takes a 1+ charge as a cation, it always exists as the diatomic ion.
a) Propose a formula for the mercury(I) ion. b)What is the formula of mercury(I) chloride?
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Propose a formula for hydrogen peroxide, a substance used as a bleaching agent. (Curiously, this compound does not behave as an acid, despite its formula. It behaves more like a classic nonmetal-nonmetal, molecular compound.)
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The uranyl cation has the formula UO22+. Propose formulas and names for the ionic compounds between the uranyl cation and F−, SO42−, and PO43−.
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The permanganate anion has the formula MnO4−. Propose formulas and names for the ionic compounds between the permanganate ion and K+, Ca2+, and Fe3+.
Answers
1.
about 1,800 electrons
3.
It is not strictly correct because of the existence of isotopes.
5.
H11, H12, and H13
7.
It is a metal.
9.
146 neutrons
11.
101.065 u
13.
3.817 × 10−23 g
15.
2.991 × 10−23 g
17.
ionic
19.
- Hg22+
- Hg2Cl2
21.
uranyl fluoride, UO2F2; uranyl sulfate, UO2SO4; uranyl phosphate, (UO2)3(PO4)2