Atomic radius/radii isotopes

Symbol Sb atomic number 51 atomic weight 121.75 Group VA (group 15) element atomic radius 1.41A ionic radius 86 + 0.76A covalent radius 1.21A electronic configuration [Kr] 4di°5s25p3 a metalloid element electronegativity 1.82 (Allred-Rochow type) valence states +5, +3, 0 and -3 isotopes and natural abundance Sb-121 (57.3%), Sb-123 (42.7%)... [Pg.48]

Symbol Cs atomic number 55 atomic weight 132.905 a Group lA (Group 1) alkali metal element electron configuration [Xe]6si atomic radius 2.65 A ionic radius (Cs ) 1.84 A ionization potential 3.89 eV valence +1 natural isotope Cs-133 37 artificial isotopes ranging in mass numbers from 112 to 148 and half-lives 17 microseconds (Cs-113) to 2.3x10 years (Cs-135). [Pg.205]

Symbol Hf atomic number 72 atomic weight 178.49 a Group IV B (Group 4) transition metal element atomic radius 1.442A electron configuration [Xe]4/i45d26s2 common valence +4, also exhibits oxidation states +2 and -i-3 most abundant natural isotope Hf-180 isotopes and their natural abundances Hf-176 (5.21%), Hf-177 (18.56%), Hf-178 (27.10%), Hf-179 (13.75%), Hf-180 (35.22%), artificial isotopes 157, 158, 168, 173, 175, 181-183. [Pg.330]

Symbol He atomic number 2 atomic weight 4.0026 a Group 0 (Group 18) inert gas element second hghtest element electron configuration Is valence 0 no chemical compound known atomic radius 0.33A isotope He-3 is found in trace concentration in He-4 natural abundance of He-3 1.37 ppm short-hved radioisotopes He-5, He-6, and He-8 are known. [Pg.335]

Symbol Fe atomic number 26 atomic weight 55.847 a Group VIII (Group 8) metallic element transition metal atomic radius 1.24A electron configuration [Ar]3d 4s2 most common valence states +2 and -i-3 other oxidization states -1, 0, -1-1, +4 and -i-6 are known but rare most abundant isotope Fe-56 natural isotopes and their abundances Fe-54 (5.90%), Fe-56 (91.52%), Fe-57 (2.245%), Fe-58 (0.33%). [Pg.410]

Symbol La atomic number 57 atomic weight 138.91 a rare-earth transition metal, precursor to a series of 14 inner-transition elements known as the lanthanide series electron configuration [XejSdiGs oxidation state -i-3 atomic radius 1.879A ionic radius (LaS+) 1.061A electronegativity 1.17 two natural isotopes are La-139 (99.911%) and La-138 (0.089%). [Pg.443]

Symbol Lu atomic number 71 atomic weight 174.97 a lanthanide series element an /-block inner-transition metal electron configuration [Xe]4/i45di6s2 valence -1-3 atomic radius (coordination number 12) 1.7349A ionic radius (Lu3+) 0.85A two naturally-occurring isotopes Lu-176 (97.1%) and Lu-175(2.59%) Lu-172 is radioactive with a half-life of 4xl0i° years (beta-emission) several artificial isotopes known, that have mass numbers 155, 156, 167—174, 177—180. [Pg.509]

Symbol Mg atomic number 12 atomic weight 24.305 a Group II A (Group 2) alkaline-earth metal atomic radius 1.60A ionic radius (Mg2+) 0.72A atomic volume 14.0 cm /mol electron configuration [Ne]3s2 valence +2 ionization potential 7.646 and 15.035eV for Mg+ and Mg2+, respectively three natural isotopes Mg-24(78.99%), Mg-25(10.00%), Mg-26(11.01%). [Pg.510]

Symbol Mn atomic number 25 atomic weight 54.938 a Group VIIB (Group 7) transition metal electron configuration [Ar]4s23d atomic radius 1.27A valence 0, -i-l, +2, -i-3, +A, +5, +6, +7 most common oxidation states +2, +A and +1] stable natural isotope Mn-55 (100%)... [Pg.538]

Symbol Nd atomic number 60 atomic weight 144.24 a rare earth lanthanide element a hght rare earth metal of cerium group an inner transition metal characterized by partially filled 4/ subshell electron configuration [Xe]4/35di6s2 most common valence state -i-3 other oxidation state +2 standard electrode potential, Nd + -i- 3e -2.323 V atomic radius 1.821 A (for CN 12) ionic radius, Nd + 0.995A atomic volume 20.60 cc/mol ionization potential 6.31 eV seven stable isotopes Nd-142 (27.13%), Nd-143 (12.20%), Nd-144 (23.87%), Nd-145 (8.29%), Nd-146 (17.18%), Nd-148 (5.72%), Nd-150 (5.60%) twenty-three radioisotopes are known in the mass range 127-141, 147, 149, 151-156. [Pg.597]

Symbol Ni atomic number 28 atomic weight 58.693 a transition metal element in the first triad of Group VIll(Group 10) after iron and cobalt electron configuration [Ar]3d 4s2 valence states 0, -i-l, +2, and -f-3 most common oxidation state +2 the standard electrode potential, NF+ -1- 2e Ni -0.237 V atomic radius 1.24A ionic radius (NF+) 0.70A five natural isotopes Ni-58 (68.08%), Ni-60 (26.22%), Ni-61 (1.14%), Ni-62 (3.63%), Ni-64 (0.93%) nineteen radioactive isotopes are known in the mass range 51-57, 59, 63, 65-74 the longest-lived radioisotope Ni-59 has a half-life 7.6x10 years. [Pg.605]

Symbol Pa atomic number 91 atomic weight 231.04 an actinide series radioactive element an inner-transition metal electron configuration [Rn]5/26di7s2 valence states +4 and +5 atomic radius 1.63A (for coordination number 12) twenty-two isotopes are known in the mass range 215-218,... [Pg.781]

Symbol Rb atomic number 37 atomic weight 85.468 a Group I (Group 1) alkali metal element electron configuration [Kr] 5si valence -i-l atomic radius 2.43A ionic radius, Rb+ 1.48A atomic volume 55.9 cc/g-atom at 20°C ionization potential 4.177 V standard electrode potential Rb+ + e Rb, E° = -2.98V two naturally-occurring isotopes, Rb-85 (72.165%) and Rb-87 (27.835%) Rb-87 radioactive, a beta emitter with a half-bfe 4.88xl0i° year twenty-seven artificial radioactive isotopes in the mass range 74—84, 86, 88-102. [Pg.795]

Symbol Na atomic number 11 atomic weight 22.9898 a Group lA (Group 1) alkali metal element electron configuration [NejSs valence +1 atomic radius 1.85A ionic radius, Na" in crystals 1.02A (for a coordination number 6) ionization potential 5.139 eV standard electrode potential, E°(Na+ + e Na) -2.71 V one naturally-occurring stable isotope, Na-23 (100%) sixteen artificial radioactive isotopes in the mass range 19-22, 24—35 longest-lived radioisotope, Na-22, ti/2 2.605 year shortest-lived isotope Na-35, ti/2 1.5 ms. [Pg.846]

Symbol Th atomic number 90 atomic weight 232.04 an actinide series radioactive element electron configuration XRn]6d27s2 valence state +4 atomic radius 1.80 A ionic radius, Th4+ 1.05 A for coordination number 8 standard electrode potential, E° for Th4+ -1- 4e Th is -1.899V all isotopes are radioactive the only naturally-occurring isotope, Th-232, ti/2 1.4xl0i° year twenty-six isotopes are known in the mass range 212-237. [Pg.927]

Symbol Tm atomic number 69 atomic weight 168.93 a lanthanide series element a rare earth metal electron configuration iXe]4/i36s2 valence +2, -i-3 atomic radius 1.73 A ionic radius, Tm " " 1.09 A for coordination number 7 one stable, natural isotope Tm-169 (100%) thirty radioisotopes in the mass range 146-168, 170-176 ty, 1.92 years. [Pg.932]