The German physicist Lothar Meyer observed a periodicity in the physical properties of the elements at about the same time that Mendeleev was working on their chemical properties. Some of Meyer’s observations can be reproduced by examining the molar volume for the solid element as a function of atomic number.

Calculate the molar volumes for the elements in Periods 2 and 3 from the densities of the elements found in Appendix 2D and the following solid densities (in g·cm^-3): nitrogen, 0.88; fluorine, 1.11; neon, 1.21. Plot your results against atomic number and explain any variations that you observe.

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Element actinium (Greek aktis, ray) aluminum (from alum, salts of the form KAl(SO4)2-12H₂O) americium (the Americas) antimony (from the Greek anti-monos, not alone; Latin stibium) argon (Greek argos, inactive) arsenic (Greek arsenikos, male) astatine (Greek astatos, unstable) barium (Greek barys, heavy) berkelium (Berkeley, California) beryllium (nom (from the mineral beryl, Be3Al2SiO18) bismuth (German weisse masse, white mass) bohrium (Niels Bohr) boron Ac Al Am Sb Ar As At Ba Bk Be Bi Bh B Symbol 89 13 95 (243) 51 121.76 18 33 85 4 (227) 26.98 83 107 39.95 56 137.33 97 (247) 5 74.92 (210) 9.01 Atomic Number, Z 208.98 (264) 10.81 Normal state s, m s, m s, m s, md g, nm s, md s, nm s, m s, m s, m s, m Molar mass, M/(g-mol-¹) s, md 10.07 2.70 13.67 6.69 1.66¹ 5.78 3.59 14.79 1.85 8.90 2.47 Density, d/(g-cm³) 1050 3200 660 2467 631 990 2600 - 189 613⁹ 300 710 986 Melting Point/C 271 Boiling Point/C 2300 1750 -186 - 350 1285 2470 1640 1650 3931 499, 1170, 1900 577, 1817, 2744 578 Ionization ization 834, 1794, 2443 1520 947, 1798 1037, 1600 502, 965 601 900, 1757 703, 1610, 2466 660 799, 2427, 3660 energies, kJ mol Electron affinity, +43 +103 <0 +78 +270 +14 <0 +91 +27 1.1 1.6 1.3. 2.1 - 2.2 2.0 0.89 1.3 1.6 2 2 +3 نسانی +3 +3 0 -3, +3, +5 -1 -3, +3, +5 +2 +3 +2 Electronegativity, y numbers. +5 +3, +5 +3 Principal oxidation Atomic radius, r/pm 188 143 173 141 174 125 217 - 113 155 128 88 118(3+) 54(3+) Ionic radius, r/pm 107(3+) 89(3+) 222(3-) 227(1-) 135(2+) 87(4+) 34(2+) 96(3+) 83(5+)* 23(3+)