{"id":2161,"date":"2018-04-11T23:52:06","date_gmt":"2018-04-12T03:52:06","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/chem1114langaracollege\/chapter\/end-of-chapter-material-2\/"},"modified":"2019-06-11T17:38:48","modified_gmt":"2019-06-11T21:38:48","slug":"end-of-chapter-material-2","status":"publish","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/chem1114langaracollege\/chapter\/end-of-chapter-material-2\/","title":{"raw":"3.6 End of Chapter Problems","rendered":"3.6 End of Chapter Problems"},"content":{"raw":"
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\r\n\r\n1. How many electrons does it take to make the mass of one proton?\r\n\r\n2. Dalton\u2019s 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?\r\n\r\n3. Give complete atomic symbols for the three known isotopes of hydrogen.\r\n\r\n4. Use its place on the periodic table to determine if indium, In, atomic number 49, is a metal or a nonmetal.\r\n\r\n5. Americium-241 is a crucial part of many smoke detectors. How many neutrons are present in its nucleus\r\n\r\n6. Determine the atomic mass of ruthenium from the given abundance and mass data.\r\n
\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
Ruthenium-96<\/td>\r\n5.54%<\/td>\r\n95.907 u<\/td>\r\n<\/tr>\r\n
Ruthenium-98<\/td>\r\n1.87%<\/td>\r\n97.905 u<\/td>\r\n<\/tr>\r\n
Ruthenium-99<\/td>\r\n12.76%<\/td>\r\n98.906 u<\/td>\r\n<\/tr>\r\n
Ruthenium-100<\/td>\r\n12.60%<\/td>\r\n99.904 u<\/td>\r\n<\/tr>\r\n
Ruthenium-101<\/td>\r\n17.06%<\/td>\r\n100.906 u<\/td>\r\n<\/tr>\r\n
Ruthenium-102<\/td>\r\n31.55%<\/td>\r\n101.904 u<\/td>\r\n<\/tr>\r\n
Ruthenium-104<\/td>\r\n18.62%<\/td>\r\n103.905 u<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/div>\r\n7. One atomic mass unit has a mass of 1.6605 \u00d7 10\u221224<\/sup> g. What is the mass of one atom of sodium?\r\n\r\n8. One atomic mass unit has a mass of 1.6605 \u00d7 10\u221224<\/sup> g. What is the mass of one molecule of H2<\/sub>O?\r\n\r\n9. From their positions on the periodic table, will Cu and I form a molecular compound or an ionic compound?\r\n\r\n10. Mercury is an unusual element in that when it takes a 1+\u00a0charge as a cation, it always exists as the diatomic ion. a) \u00a0Propose a formula for the mercury(I) ion. \u00a0b)What is the formula of mercury(I) chloride?\r\n\r\n11. The uranyl cation has the formula UO2<\/sub>2+<\/sup>. Propose formulas and names for the ionic compounds between the uranyl cation and F\u2212<\/sup>, SO4<\/sub>2\u2212<\/sup>, and PO4<\/sub>3\u2212<\/sup>.\r\n\r\n12. Using a periodic table, identify the element symbol and group name for the following elements and identify it as either a metal, non-metal or metalloid:\r\na) Rubidium \u00a0 \u00a0 \u00a0b)\u00a0 Strontium \u00a0 \u00a0 \u00a0c)\u00a0 Californium \u00a0 \u00a0 \u00a0d)\u00a0 Aluminum (no group name required)\r\ne)\u00a0 Iodine \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 f)\u00a0\u00a0 Krypton \u00a0 \u00a0 \u00a0 \u00a0g)\u00a0 Tin (no group name required)\r\n\r\n13. List 5 transition metals with their name, element symbol and atomic number.\r\n\r\n14. What is a diatomic element? Give several examples.\r\n\r\n15. Explain the experiment and findings of each of the following scientists:\r\na) Rutherford \u00a0 \u00a0 \u00a0 b) J. J. Thompson \u00a0 \u00a0 \u00a0c)\u00a0 Millikan\r\n\r\n16. Use Dalton\u2019s theory to explain why potassium nitrate from India or Italy has the same mass percents (or ratios) of K, N and O.\r\n\r\n17. Street drugs are often mixed with an inactive substance, such as ascorbic acid (vitamin C). By separating a drug mixture into component substances and calculating the mass of vitamin C per gram of sample, government chemists can track the drug\u2019s distribution. For example, if different cocaine samples from New York, L. A. and Paris all contain 0.6384 g of vitamin C per gram of sample, they likely come from a common source. Is this street sample a compound, element or mixture? In this case, does the constant mass ratio of the components exemplify the law of constant composition? Explain.\r\n\r\n18. For each of the following, based on the info given, fill in the blanks:\r\n\r\na) Zn, Z = 30, neutrons = 34, atomic number = ?, protons = ?\r\nb) Protons = 53, neutrons = 74, symbol = ?, mass number = ?, A = ?, Z = ?\r\nc)\u00a0 Eu, Z = ?, A = 153, protons = ?, neutrons = ?\r\n\r\n19. \u00a0Complete the following table:\r\n\r\n<\/div>\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
Symbol<\/strong><\/td>\r\nElement<\/strong><\/td>\r\nProtons<\/strong><\/td>\r\nNeutrons<\/strong><\/td>\r\nElectrons<\/strong><\/td>\r\nMass Number<\/strong>\r\n\r\n(A)<\/strong><\/td>\r\nAtomic number<\/strong>\r\n\r\n(Z)<\/strong><\/td>\r\n<\/tr>\r\n
38<\/sup>Ar<\/td>\r\n<\/td>\r\n<\/td>\r\n<\/td>\r\n<\/td>\r\n<\/td>\r\n<\/td>\r\n<\/tr>\r\n
<\/td>\r\nMagnesium<\/td>\r\n<\/td>\r\n13<\/td>\r\n<\/td>\r\n<\/td>\r\n<\/td>\r\n<\/tr>\r\n
<\/td>\r\n<\/td>\r\n<\/td>\r\n<\/td>\r\n18<\/td>\r\n37<\/td>\r\n17<\/td>\r\n<\/tr>\r\n
$latex _{27}^{60}\\text{Co}$<\/td>\r\n<\/td>\r\n<\/td>\r\n<\/td>\r\n<\/td>\r\n<\/td>\r\n<\/td>\r\n<\/tr>\r\n
<\/td>\r\nNickel<\/td>\r\n<\/td>\r\n<\/td>\r\n28<\/td>\r\n60<\/td>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n20. \u00a0Write the complete atomic symbol for each of the following isotopes and state the number of protons, electrons and neutrons for each:\r\na) Fluorine with a mass number of 18 \u00a0 \u00a0 \u00a0 b)\u00a0 Atomic number\u00a0of 7 and 8 neutrons\r\nc)\u00a0 Z = 18, neutrons = 22 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0d)\u00a0 He, with A = 3\r\ne)\u00a0 Z = 82, A = 207 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 f)\u00a0 Beryllium with 5 neutrons\r\n\r\n21. \u00a0How many electrons are present in the following ions:\r\n\r\na)Fe3+<\/sup>\u00a0\u00a0 b) Cu+<\/sup>\u00a0\u00a0 c) Ni2+<\/sup>\u00a0\u00a0 d) Br-<\/sup>\u00a0\u00a0 e) Eu3+<\/sup>\u00a0\u00a0 f) P3-<\/sup>\r\n\r\n22. \u00a0List the number of protons, electrons and neutrons for the following:\r\n\r\na) \u00a0$latex _{82}^{208}\\text{Pb}^{2+}$ \u00a0 \u00a0 \u00a0 b) \u00a0$latex _{7}^{14}\\text{N}^{3-}$\r\n\r\n23. \u00a0List the number of atoms present in a molecule (or formula unit) of:\r\na) NaNO3<\/sub> b) C2<\/sub>H5<\/sub>OH\u00a0\u00a0\u00a0 c) Fe(ClO4<\/sub>)3<\/sub>\r\n\r\n<\/div>\r\n

24. Gallium has 2 naturally occurring isotopes, 69<\/sup>Ga (isotopic mass = 68.9256 amu, percent abundance = 60.11%) and 71<\/sup>Ga (isotopic mass = 70.9247 amu, percent abundance = 39.89%). Calculate the average atomic mass of Gallium.<\/p>\r\n

25. Chlorine has 2 naturally occurring isotopes, 35<\/sup>Cl (isotopic mass = 34.9689 amu) and 37<\/sup>Cl (isotopic mass = 36.9659). If the average atomic mass of Cl is 35.4527 amu, what is the percent abundance of each isotope?<\/p>\r\n

26. The two naturally occurring isotopes of nitrogen have masses of 14.0031 amu and 15.0001 amu, respectively. Determine the percentage of 15<\/sup>N atoms in naturally occurring nitrogen with average atomic mass of 14.0067 amu. \u00a0(Hint, the TOTAL abundance of the two isotopes must = 100%.)<\/p>\r\n \r\n

Answers<\/strong><\/h2>\r\n1. \u00a0About 1,800 electrons\r\n\r\n2. \u00a0It is not strictly correct because of the existence of isotopes.\r\n\r\n3. \u00a0$latex _{1}^{1}\\text{H}$, $latex _{1}^{2}\\text{H}$, and $latex _{1}^{3}\\text{H}$\r\n\r\n4. \u00a0It is a metal.\r\n\r\n5. \u00a0146 neutrons\r\n\r\n6. \u00a0101.065 u\r\n\r\n7. \u00a03.817 \u00d7 10\u221223<\/sup> g\r\n\r\n8. \u00a02.991 \u00d7 10\u221223<\/sup> g\r\n\r\n9. \u00a0ionic\r\n\r\n10. \u00a0a)\u00a0Hg2<\/sub>2+<\/sup> \u00a0 \u00a0 \u00a0 \u00a0b)\u00a0Hg2<\/sub>Cl2<\/sub>\r\n\r\n11. \u00a0Uranyl fluoride, UO2<\/sub>F2<\/sub>; uranyl sulfate, UO2<\/sub>SO4<\/sub>; uranyl phosphate, (UO2<\/sub>)3<\/sub>(PO4<\/sub>)2<\/sub>\r\n\r\n12. \u00a0a) Rb, alkali metal, metal \u00a0 \u00a0 \u00a0b) Sr, alkaline earth metal, metal \u00a0 \u00a0 \u00a0c) Cf, actinide, metal\r\nd) Al (no group name required), metal \u00a0 \u00a0 \u00a0e) I, halogen, non-metal \u00a0 \u00a0 \u00a0f) Kr, nobel gas, non-metal\r\ng) Sn (no group name required), metal\r\n

13.\u00a0 <\/span>(Variety of answers possible)<\/p>\r\n

14.\u00a0 <\/span>An element that exists in the natural state as 2 atoms bonded together in a molecule. Examples include H2<\/sub>, O2<\/sub>, N2<\/sub>, halogens<\/p>\r\n

15.\u00a0 <\/span>a) Rutherford: performed an experiment where he shot alpha particles at gold foil. He observed that many alphas were deflected and some bounced back, suggesting that Thompson\u2019s view of the atom was incorrect. Instead, he proposed that atom had a nucleus of positive charge, surrounded by a \u201csea\u201d of negative charge (electrons)<\/p>\r\n

b) J. J. Thompson: used a cathode ray tube (consisting of a negatively charged beam), and calculations regarding the deflection of the beam in a magnetic or electric field, to calculate the mass\/charge ratio of the electron.<\/p>\r\n

c) Millikan: performed an experiment where, in a mist of oil in air, droplets were covered with electrons (resulting from an X-ray hitting gas molecules in the air). He measured the rate of fall of these charged oil droplets through an electric field, and from this he determined the actual charge of an electron, and thus (in conjunction with Thompson\u2019s work) the mass of an electron.<\/p>\r\n

16.\u00a0 <\/span>The law of constant composition tells us that a given compound will always have the same mass percents of its components. Dalton used this idea, and his concept of the atom, to form his forth postulate, which states that atoms combine in fixed ratios of whole numbers to form compounds. If ratios remain the same, and the masses of each constituent atom are the same, the mass percents will remain the same regardless of the size of the sample.<\/p>\r\n

17.\u00a0 <\/span>It is a mixture. It does not exemplify the law of constant composition. The \u201cconstant\u201d composition results from the fact that they are all part of the same mixture (same source), but the composition COULD have varied and still produced a mixture of cocaine and vitamin C (with a different amount of vitamin C per sample) depending on the manufacturer.<\/p>\r\n

18.\u00a0 <\/span>a) Zn: atomic number = 30, protons = 30\r\nb) symbol = I (or a more complete symbol =\u00a0$latex _{53}^{127}\\text{I}$<\/span>),\u00a0\u00a0<\/span>mass number = 127, A = 127, Z = 53\r\nc) Eu: Z = 63, protons = 63, neutrons = 90<\/p>\r\n

19.\u00a0<\/span><\/p>\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
Symbol<\/strong><\/td>\r\nElement<\/strong><\/td>\r\nProtons<\/strong><\/td>\r\nNeutrons<\/strong><\/td>\r\nElectrons<\/strong><\/td>\r\nMass Number<\/strong>\r\n\r\n(A)<\/strong><\/td>\r\nAtomic number<\/strong>\r\n\r\n(Z)<\/strong><\/td>\r\n<\/tr>\r\n
38<\/sup>Ar<\/td>\r\nArgon<\/td>\r\n18<\/td>\r\n20<\/td>\r\n18<\/td>\r\n38<\/td>\r\n18<\/td>\r\n<\/tr>\r\n
\u00a0$latex _{12}^{25}\\text{Mg}$<\/td>\r\nMagnesium<\/td>\r\n\u00a012<\/td>\r\n13<\/td>\r\n\u00a012<\/td>\r\n\u00a025<\/td>\r\n\u00a012<\/td>\r\n<\/tr>\r\n
\u00a0$latex _{17}^{37}\\text{Cl}^{-}$<\/td>\r\n\u00a0Chlorine<\/td>\r\n\u00a017<\/td>\r\n\u00a020<\/td>\r\n18<\/td>\r\n37<\/td>\r\n17<\/td>\r\n<\/tr>\r\n
$latex _{27}^{60}\\text{Co}$<\/td>\r\n\u00a0Cobalt<\/td>\r\n\u00a027<\/td>\r\n\u00a033<\/td>\r\n\u00a027<\/td>\r\n\u00a060<\/td>\r\n\u00a027<\/td>\r\n<\/tr>\r\n
$latex _{28}^{60}\\text{Ni}$<\/td>\r\nNickel<\/td>\r\n28<\/td>\r\n\u00a032<\/td>\r\n28<\/td>\r\n60<\/td>\r\n\u00a028<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n

20.\u00a0 <\/span>a) 18<\/sup>9<\/sub>F, p = 9, e = 9, n = 9 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0b) 15<\/sup>7<\/sub>N, p = 7, e = 7, n = 8\r\nc) 40<\/sup>18<\/sub>Ar, p = 18, n = 22, e = 18 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0d) 3<\/sup>2<\/sub>He, p = 2, e = 2, n = 1\r\ne)\u00a0 <\/span>207<\/sup>82<\/sub>Pb, p = 82, e = 82, n = 125 \u00a0 \u00a0 \u00a0f) 9<\/sup>4<\/sub>Be, p = 4, n = 5, e = 4<\/span><\/p>\r\n

21.\u00a0 <\/span>a) 23\u00a0 \u00a0 \u00a0\u00a0<\/span>b) 28 \u00a0 \u00a0\u00a0\u00a0 <\/span>c) 26\u00a0 \u00a0 \u00a0 \u00a0<\/span>d) 36 \u00a0 \u00a0\u00a0\u00a0<\/span>e) 60 \u00a0 \u00a0\u00a0\u00a0 <\/span>f) 18<\/span><\/p>\r\n

22.\u00a0 <\/span>a) p = 82, n = 126, e = 80 \u00a0 \u00a0 \u00a0 \u00a0\u00a0b) p = 7, n = 7, e = 10<\/span><\/p>\r\n

23.\u00a0 <\/span>a) 1 atom of Na, 1 atom of N and 3 atoms of O \u00a0(5 atoms total)\r\nb) 2 atoms of C, 6 atoms of H and 1 atom of O \u00a0(9 atoms total)\r\nc) 1 atom of Fe, 3 atoms of Cl and 12 atoms of O \u00a0(16 atoms total)<\/p>\r\n

24. \u00a069.72 amu<\/p>\r\n

25. \u00a075.774% 35<\/sup>Cl and 24.226% 37<\/sup>Cl<\/p>\r\n

26. \u00a00.36% 15<\/sup>N<\/p>\r\n\r\n<\/div>","rendered":"

\n
\n
\n

1. How many electrons does it take to make the mass of one proton?<\/p>\n

2. Dalton\u2019s 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?<\/p>\n

3. Give complete atomic symbols for the three known isotopes of hydrogen.<\/p>\n

4. Use its place on the periodic table to determine if indium, In, atomic number 49, is a metal or a nonmetal.<\/p>\n

5. Americium-241 is a crucial part of many smoke detectors. How many neutrons are present in its nucleus<\/p>\n

6. Determine the atomic mass of ruthenium from the given abundance and mass data.<\/p>\n

\n\n\n\n\n\n\n\n\n\n
Ruthenium-96<\/td>\n5.54%<\/td>\n95.907 u<\/td>\n<\/tr>\n
Ruthenium-98<\/td>\n1.87%<\/td>\n97.905 u<\/td>\n<\/tr>\n
Ruthenium-99<\/td>\n12.76%<\/td>\n98.906 u<\/td>\n<\/tr>\n
Ruthenium-100<\/td>\n12.60%<\/td>\n99.904 u<\/td>\n<\/tr>\n
Ruthenium-101<\/td>\n17.06%<\/td>\n100.906 u<\/td>\n<\/tr>\n
Ruthenium-102<\/td>\n31.55%<\/td>\n101.904 u<\/td>\n<\/tr>\n
Ruthenium-104<\/td>\n18.62%<\/td>\n103.905 u<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

7. One atomic mass unit has a mass of 1.6605 \u00d7 10\u221224<\/sup> g. What is the mass of one atom of sodium?<\/p>\n

8. One atomic mass unit has a mass of 1.6605 \u00d7 10\u221224<\/sup> g. What is the mass of one molecule of H2<\/sub>O?<\/p>\n

9. From their positions on the periodic table, will Cu and I form a molecular compound or an ionic compound?<\/p>\n

10. Mercury is an unusual element in that when it takes a 1+\u00a0charge as a cation, it always exists as the diatomic ion. a) \u00a0Propose a formula for the mercury(I) ion. \u00a0b)What is the formula of mercury(I) chloride?<\/p>\n

11. The uranyl cation has the formula UO2<\/sub>2+<\/sup>. Propose formulas and names for the ionic compounds between the uranyl cation and F\u2212<\/sup>, SO4<\/sub>2\u2212<\/sup>, and PO4<\/sub>3\u2212<\/sup>.<\/p>\n

12. Using a periodic table, identify the element symbol and group name for the following elements and identify it as either a metal, non-metal or metalloid:
\na) Rubidium \u00a0 \u00a0 \u00a0b)\u00a0 Strontium \u00a0 \u00a0 \u00a0c)\u00a0 Californium \u00a0 \u00a0 \u00a0d)\u00a0 Aluminum (no group name required)
\ne)\u00a0 Iodine \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 f)\u00a0\u00a0 Krypton \u00a0 \u00a0 \u00a0 \u00a0g)\u00a0 Tin (no group name required)<\/p>\n

13. List 5 transition metals with their name, element symbol and atomic number.<\/p>\n

14. What is a diatomic element? Give several examples.<\/p>\n

15. Explain the experiment and findings of each of the following scientists:
\na) Rutherford \u00a0 \u00a0 \u00a0 b) J. J. Thompson \u00a0 \u00a0 \u00a0c)\u00a0 Millikan<\/p>\n

16. Use Dalton\u2019s theory to explain why potassium nitrate from India or Italy has the same mass percents (or ratios) of K, N and O.<\/p>\n

17. Street drugs are often mixed with an inactive substance, such as ascorbic acid (vitamin C). By separating a drug mixture into component substances and calculating the mass of vitamin C per gram of sample, government chemists can track the drug\u2019s distribution. For example, if different cocaine samples from New York, L. A. and Paris all contain 0.6384 g of vitamin C per gram of sample, they likely come from a common source. Is this street sample a compound, element or mixture? In this case, does the constant mass ratio of the components exemplify the law of constant composition? Explain.<\/p>\n

18. For each of the following, based on the info given, fill in the blanks:<\/p>\n

a) Zn, Z = 30, neutrons = 34, atomic number = ?, protons = ?
\nb) Protons = 53, neutrons = 74, symbol = ?, mass number = ?, A = ?, Z = ?
\nc)\u00a0 Eu, Z = ?, A = 153, protons = ?, neutrons = ?<\/p>\n

19. \u00a0Complete the following table:<\/p>\n<\/div>\n\n\n\n\n\n\n\n\n
Symbol<\/strong><\/td>\nElement<\/strong><\/td>\nProtons<\/strong><\/td>\nNeutrons<\/strong><\/td>\nElectrons<\/strong><\/td>\nMass Number<\/strong><\/p>\n

(A)<\/strong><\/td>\n

Atomic number<\/strong><\/p>\n

(Z)<\/strong><\/td>\n<\/tr>\n

38<\/sup>Ar<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
<\/td>\nMagnesium<\/td>\n<\/td>\n13<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
<\/td>\n<\/td>\n<\/td>\n<\/td>\n18<\/td>\n37<\/td>\n17<\/td>\n<\/tr>\n
[latex]_{27}^{60}\\text{Co}[\/latex]<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
<\/td>\nNickel<\/td>\n<\/td>\n<\/td>\n28<\/td>\n60<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

20. \u00a0Write the complete atomic symbol for each of the following isotopes and state the number of protons, electrons and neutrons for each:
\na) Fluorine with a mass number of 18 \u00a0 \u00a0 \u00a0 b)\u00a0 Atomic number\u00a0of 7 and 8 neutrons
\nc)\u00a0 Z = 18, neutrons = 22 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0d)\u00a0 He, with A = 3
\ne)\u00a0 Z = 82, A = 207 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 f)\u00a0 Beryllium with 5 neutrons<\/p>\n

21. \u00a0How many electrons are present in the following ions:<\/p>\n

a)Fe3+<\/sup>\u00a0\u00a0 b) Cu+<\/sup>\u00a0\u00a0 c) Ni2+<\/sup>\u00a0\u00a0 d) Br–<\/sup>\u00a0\u00a0 e) Eu3+<\/sup>\u00a0\u00a0 f) P3-<\/sup><\/p>\n

22. \u00a0List the number of protons, electrons and neutrons for the following:<\/p>\n

a) \u00a0[latex]_{82}^{208}\\text{Pb}^{2+}[\/latex] \u00a0 \u00a0 \u00a0 b) \u00a0[latex]_{7}^{14}\\text{N}^{3-}[\/latex]<\/p>\n

23. \u00a0List the number of atoms present in a molecule (or formula unit) of:
\na) NaNO3<\/sub> b) C2<\/sub>H5<\/sub>OH\u00a0\u00a0\u00a0 c) Fe(ClO4<\/sub>)3<\/sub><\/p>\n<\/div>\n

24. Gallium has 2 naturally occurring isotopes, 69<\/sup>Ga (isotopic mass = 68.9256 amu, percent abundance = 60.11%) and 71<\/sup>Ga (isotopic mass = 70.9247 amu, percent abundance = 39.89%). Calculate the average atomic mass of Gallium.<\/p>\n

25. Chlorine has 2 naturally occurring isotopes, 35<\/sup>Cl (isotopic mass = 34.9689 amu) and 37<\/sup>Cl (isotopic mass = 36.9659). If the average atomic mass of Cl is 35.4527 amu, what is the percent abundance of each isotope?<\/p>\n

26. The two naturally occurring isotopes of nitrogen have masses of 14.0031 amu and 15.0001 amu, respectively. Determine the percentage of 15<\/sup>N atoms in naturally occurring nitrogen with average atomic mass of 14.0067 amu. \u00a0(Hint, the TOTAL abundance of the two isotopes must = 100%.)<\/p>\n

 <\/p>\n

Answers<\/strong><\/h2>\n

1. \u00a0About 1,800 electrons<\/p>\n

2. \u00a0It is not strictly correct because of the existence of isotopes.<\/p>\n

3. \u00a0[latex]_{1}^{1}\\text{H}[\/latex], [latex]_{1}^{2}\\text{H}[\/latex], and [latex]_{1}^{3}\\text{H}[\/latex]<\/p>\n

4. \u00a0It is a metal.<\/p>\n

5. \u00a0146 neutrons<\/p>\n

6. \u00a0101.065 u<\/p>\n

7. \u00a03.817 \u00d7 10\u221223<\/sup> g<\/p>\n

8. \u00a02.991 \u00d7 10\u221223<\/sup> g<\/p>\n

9. \u00a0ionic<\/p>\n

10. \u00a0a)\u00a0Hg2<\/sub>2+<\/sup> \u00a0 \u00a0 \u00a0 \u00a0b)\u00a0Hg2<\/sub>Cl2<\/sub><\/p>\n

11. \u00a0Uranyl fluoride, UO2<\/sub>F2<\/sub>; uranyl sulfate, UO2<\/sub>SO4<\/sub>; uranyl phosphate, (UO2<\/sub>)3<\/sub>(PO4<\/sub>)2<\/sub><\/p>\n

12. \u00a0a) Rb, alkali metal, metal \u00a0 \u00a0 \u00a0b) Sr, alkaline earth metal, metal \u00a0 \u00a0 \u00a0c) Cf, actinide, metal
\nd) Al (no group name required), metal \u00a0 \u00a0 \u00a0e) I, halogen, non-metal \u00a0 \u00a0 \u00a0f) Kr, nobel gas, non-metal
\ng) Sn (no group name required), metal<\/p>\n

13.\u00a0 <\/span>(Variety of answers possible)<\/p>\n

14.\u00a0 <\/span>An element that exists in the natural state as 2 atoms bonded together in a molecule. Examples include H2<\/sub>, O2<\/sub>, N2<\/sub>, halogens<\/p>\n

15.\u00a0 <\/span>a) Rutherford: performed an experiment where he shot alpha particles at gold foil. He observed that many alphas were deflected and some bounced back, suggesting that Thompson\u2019s view of the atom was incorrect. Instead, he proposed that atom had a nucleus of positive charge, surrounded by a \u201csea\u201d of negative charge (electrons)<\/p>\n

b) J. J. Thompson: used a cathode ray tube (consisting of a negatively charged beam), and calculations regarding the deflection of the beam in a magnetic or electric field, to calculate the mass\/charge ratio of the electron.<\/p>\n

c) Millikan: performed an experiment where, in a mist of oil in air, droplets were covered with electrons (resulting from an X-ray hitting gas molecules in the air). He measured the rate of fall of these charged oil droplets through an electric field, and from this he determined the actual charge of an electron, and thus (in conjunction with Thompson\u2019s work) the mass of an electron.<\/p>\n

16.\u00a0 <\/span>The law of constant composition tells us that a given compound will always have the same mass percents of its components. Dalton used this idea, and his concept of the atom, to form his forth postulate, which states that atoms combine in fixed ratios of whole numbers to form compounds. If ratios remain the same, and the masses of each constituent atom are the same, the mass percents will remain the same regardless of the size of the sample.<\/p>\n

17.\u00a0 <\/span>It is a mixture. It does not exemplify the law of constant composition. The \u201cconstant\u201d composition results from the fact that they are all part of the same mixture (same source), but the composition COULD have varied and still produced a mixture of cocaine and vitamin C (with a different amount of vitamin C per sample) depending on the manufacturer.<\/p>\n

18.\u00a0 <\/span>a) Zn: atomic number = 30, protons = 30
\nb) symbol = I (or a more complete symbol =\u00a0[latex]_{53}^{127}\\text{I}[\/latex]<\/span>),\u00a0\u00a0<\/span>mass number = 127, A = 127, Z = 53
\nc) Eu: Z = 63, protons = 63, neutrons = 90<\/p>\n

19.\u00a0<\/span><\/p>\n\n\n\n\n\n\n\n\n
Symbol<\/strong><\/td>\nElement<\/strong><\/td>\nProtons<\/strong><\/td>\nNeutrons<\/strong><\/td>\nElectrons<\/strong><\/td>\nMass Number<\/strong><\/p>\n

(A)<\/strong><\/td>\n

Atomic number<\/strong><\/p>\n

(Z)<\/strong><\/td>\n<\/tr>\n

38<\/sup>Ar<\/td>\nArgon<\/td>\n18<\/td>\n20<\/td>\n18<\/td>\n38<\/td>\n18<\/td>\n<\/tr>\n
\u00a0[latex]_{12}^{25}\\text{Mg}[\/latex]<\/td>\nMagnesium<\/td>\n\u00a012<\/td>\n13<\/td>\n\u00a012<\/td>\n\u00a025<\/td>\n\u00a012<\/td>\n<\/tr>\n
\u00a0[latex]_{17}^{37}\\text{Cl}^{-}[\/latex]<\/td>\n\u00a0Chlorine<\/td>\n\u00a017<\/td>\n\u00a020<\/td>\n18<\/td>\n37<\/td>\n17<\/td>\n<\/tr>\n
[latex]_{27}^{60}\\text{Co}[\/latex]<\/td>\n\u00a0Cobalt<\/td>\n\u00a027<\/td>\n\u00a033<\/td>\n\u00a027<\/td>\n\u00a060<\/td>\n\u00a027<\/td>\n<\/tr>\n
[latex]_{28}^{60}\\text{Ni}[\/latex]<\/td>\nNickel<\/td>\n28<\/td>\n\u00a032<\/td>\n28<\/td>\n60<\/td>\n\u00a028<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

20.\u00a0 <\/span>a) 18<\/sup>9<\/sub>F, p = 9, e = 9, n = 9 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0b) 15<\/sup>7<\/sub>N, p = 7, e = 7, n = 8
\nc) 40<\/sup>18<\/sub>Ar, p = 18, n = 22, e = 18 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0d) 3<\/sup>2<\/sub>He, p = 2, e = 2, n = 1
\ne)\u00a0 <\/span>207<\/sup>82<\/sub>Pb, p = 82, e = 82, n = 125 \u00a0 \u00a0 \u00a0f) 9<\/sup>4<\/sub>Be, p = 4, n = 5, e = 4<\/span><\/p>\n

21.\u00a0 <\/span>a) 23\u00a0 \u00a0 \u00a0\u00a0<\/span>b) 28 \u00a0 \u00a0\u00a0\u00a0 <\/span>c) 26\u00a0 \u00a0 \u00a0 \u00a0<\/span>d) 36 \u00a0 \u00a0\u00a0\u00a0<\/span>e) 60 \u00a0 \u00a0\u00a0\u00a0 <\/span>f) 18<\/span><\/p>\n

22.\u00a0 <\/span>a) p = 82, n = 126, e = 80 \u00a0 \u00a0 \u00a0 \u00a0\u00a0b) p = 7, n = 7, e = 10<\/span><\/p>\n

23.\u00a0 <\/span>a) 1 atom of Na, 1 atom of N and 3 atoms of O \u00a0(5 atoms total)
\nb) 2 atoms of C, 6 atoms of H and 1 atom of O \u00a0(9 atoms total)
\nc) 1 atom of Fe, 3 atoms of Cl and 12 atoms of O \u00a0(16 atoms total)<\/p>\n

24. \u00a069.72 amu<\/p>\n

25. \u00a075.774% 35<\/sup>Cl and 24.226% 37<\/sup>Cl<\/p>\n

26. \u00a00.36% 15<\/sup>N<\/p>\n<\/div>\n","protected":false},"author":330,"menu_order":7,"template":"","meta":{"pb_show_title":"on","pb_short_title":"3.6 End of Chapter Problems","pb_subtitle":"","pb_authors":[],"pb_section_license":"cc-by-nc-sa"},"chapter-type":[],"contributor":[],"license":[54],"class_list":["post-2161","chapter","type-chapter","status-publish","hentry","license-cc-by-nc-sa"],"part":1293,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/chem1114langaracollege\/wp-json\/pressbooks\/v2\/chapters\/2161","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/chem1114langaracollege\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/chem1114langaracollege\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/chem1114langaracollege\/wp-json\/wp\/v2\/users\/330"}],"version-history":[{"count":16,"href":"https:\/\/pressbooks.bccampus.ca\/chem1114langaracollege\/wp-json\/pressbooks\/v2\/chapters\/2161\/revisions"}],"predecessor-version":[{"id":4916,"href":"https:\/\/pressbooks.bccampus.ca\/chem1114langaracollege\/wp-json\/pressbooks\/v2\/chapters\/2161\/revisions\/4916"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/chem1114langaracollege\/wp-json\/pressbooks\/v2\/parts\/1293"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/chem1114langaracollege\/wp-json\/pressbooks\/v2\/chapters\/2161\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/chem1114langaracollege\/wp-json\/wp\/v2\/media?parent=2161"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/chem1114langaracollege\/wp-json\/pressbooks\/v2\/chapter-type?post=2161"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/chem1114langaracollege\/wp-json\/wp\/v2\/contributor?post=2161"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/chem1114langaracollege\/wp-json\/wp\/v2\/license?post=2161"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}