Valence configurations symbols

In the sodium atom pairs of 3/2 states result from the promotion of the 3s valence electron to any np orbital with n > 2. It is convenient to label the states with this value of n, as n P 1/2 and n f 3/2, the n label being helpful for states that arise when only one electron is promoted and the unpromoted electrons are either in filled orbitals or in an x orbital. The n label can be used, therefore, for hydrogen, the alkali metals, helium and the alkaline earths. In other atoms it is usual to precede the state symbols by the configuration of the electrons in unfilled orbitals, as in the 2p3p state of carbon. 

This idea is readily extended to simple molecules of compounds formed by nonmetal atoms. An example is the HF molecule. You will recall that a fluorine atom has the electron configuration ls22s22p5. ft has seven electrons in its outermost principal energy level (n = 2). These are referred to as valence electrons, in contrast to the core electrons filling the principal level, n = 1. If the valence electrons are shown as dots around the symbol of the element, the fluorine atom can be represented as... 

The Lewis symbol for nitrogen, for example, represents the valence electron configuration 2s22pA.12p>112p 1 (see 1), with two electrons paired in a 2s-orbital and three unpaired electrons in different 2p-orbitals. The Lewis symbol is a visual summary of the valence-shell electron configuration of an atom and allows us to see what happens to the electrons when an ion forms. 

The oxygen atom, with valence electron configuration 2s12px12pv 12p J, has two electrons with unpaired spins (its Lewis symbol is -O-, which we abbreviate to -0-). Two radicals are also produced when the oxygen atom attacks a hydrogen molecule ... 

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%)... 

Symbol As atomic number 33 atomic weight 74.922 covalent radius AsS+ 1.2 lA electron configuration [Ar] 4s23di°4p3 a Group VA (Group 15) metalloid element electronegativity 2.20 (Allred-Rochow type) principal valence states, -1-5, +3, 0, and -3 stable isotope As-75. 

Symbol Ba atomic number 56 atomic weight 137.327 a Group llA (Group 2) alkaline earth element electronic configuration [Xejs valence state +2 ionic radius of Ba2+ in crystal (corresponding to coordination number 8) 1.42 A first ionization potential lO.OOeV stable isotopes and their percent abundances Ba-138 (71.70), Ba-137 (11.23), Ba-136 (7.85), Ba-135 (6.59), Ba-134 (2.42) minor isotopes Ba-130 (0.106) and Ba-132 (0.101) also twenty-two radioisotopes are known. 

Symbol B atomic number 5 atomic weight 10.811 a Group III A (Group 13) metalloid element atomic volume 4.70 cc/g-atom electron affinity 0.277 eV electronic configuration Is22s22pi valence state +3 naturally occurring stable isotopes are B-10 and B-11 and their abundance 19.57% and 80.43%, respectively. 

Symbol Br atomic number 35 atomic weight 79.904 a halogen group element electron affinity 3.36359 eV electronegativity 2.8 electron configuration [Ar] 3di°4s24p5 most stable valence states -1 and -i-5, less stable valence states -1-1 and -i-3 a diatomic molecule (Br2) in liquid and vapor states over a wide range of temperature two stable isotopes, Br-79 (50.57%) and Br-81 (49.43%). 

Symbol Cd atomic number 48 atomic weight 112.41 a Group IIB (Group 12) metallic element ionization potential 8.994eV electron configuration [Kr]4di°5s2 valence state +2 standard electrode potential, E° -0.40V. The isotopes and their natural relative abundance are ... 

Symbol Ca atomic number 20 atomic weight 40.078 a Group IIA (Group 2) alkaline-earth metaUic element ionic radius 1.06 A (Ca2+) electron configuration [Ar]4s2 valence state +2 standard electrode potential, E° = -2.87V stable isotopes and their abundance Ca-40 (97.00%), Ca-44 (2.06%) Ca-42 (0.64%), Ca-48 (0.18%), Ca-43 (0.145%), and Ca-46 (0.003%) also the element has six unstable isotopes of which Ca-41 has the longest half-life, l.lxlO yr (decay mode electron capture), and Ca-38 has shortest half life 0.66 sec (P-decay). 

Symbol Cf atomic number 98 atomic weight 251 (the principal isotope) californium is a transuranium radioactive actinide element electron configuration [Rn]5/i°7s2 valence state +3 most stable isotope Cf, half-life 800 years isotope properties are presented below ... 

Symbol Ce atomic number 58 atomic weight 140.115 a rare-earth metal a lanthanide series inner-transition /-block element metaUic radius (alpha form) 1.8247A(CN=12) atomic volume 20.696 cm /mol electronic configuration [Xe]4fi5di6s2 common valence states -i-3 and +4 four stable isotopes Ce-140 and Ce-142 are the two major ones, their percent abundances 88.48% and 11.07%, respectively. Ce—138 (0.25%) and Ce—136(0.193%) are minor isotopes several artificial radioactive isotopes including Ce-144, a major fission product (ti 284.5 days), are known. 

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). 

Symbol Co atomic number 27 atomic weight 58.933 a transtion metal, Group VIll (Group 9) element electron configuration [Ar]3d 4s2 valence +2 and +3 also valences 0, +1, +4, and +5 are known natural isotopes Co-59 (99.8%) and Co-57 (0.2%) radioactive isotope Co-60. 

Symbol Cm atomic number 96 atomic weight 247 a radioactive transuranium actinide series element electron configuration [Rn]5/ 6di7s2 most stable valence state +3 most stable isotope Cm-247. Curium isotopes, half-hves and decay modes are ... 

Symbol Dy atomic number 66 atomic weight 162.50 a lanthanide series, inner transition, rare earth metal electron configuration [Xe]4 5di6s2 atomic volume 19.032 cm /g. atom atomic radius 1.773A ionic radius 0.908A most common valence state +3. 

Symbol Eu atomic number 63 atomic weight 151.97 a lanthanide group inner transition metal electron configuration [Xe]4/ 5di6s2 (partially filled orbitals) valence states +3 and +2. 

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. 

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. 

Symbol Ho atomic number 67 atomic weight 164.93 a lanthanide series rare earth element electron configuration [Xe]4/ii6s2 valence state +3 metallic radius (coordination number 12) 1.767A atomic volume 18.78 cc/mol ionic radius Ho3+ 0.894A one naturally occurring isotope. Ho-165. 

Symbol H atomic number 1 atomic weight 1.0079 the lightest of all the chemical elements the first element in the Periodic Table Group lA (group 1) nonmetallic gaseous element occurs as H2, a diatomic molecule electron configuration Ish valences -i-l and-1 three isotopes H-1 or protium (99.9844%), H-2 or deuterium (0.0156%), H-3 or tritium (radioactive, ty, =12.4 yr., in traces... 

Symbol In atomic number 49 atomic weight 114.82 a Group IIIA (Group 13) metalhc element electron configuration [Kr]4di°5s25pi most common valence state +3 also exhibits valence +2 and +1 two stable isotopes. In-113 (4.23%),... 

Symbol Ir atomic number 77 atomic weight 192.22 a Group VIII (Group 8) transition metal electron configuration [Xe]4/i45d 6s2 common valence states -1-3 and +4 valence states 0, -i-l, +2, -i-5 and -i-6 are known two natural isotopes, lr-191 (37.30%) and Ir-193 (62.70%) The element has 28 radioisotopes, ranging in masses from 170 to 198. 

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%). 

Symbol Kr atomic number 36 atomic weight 83.80 a Group 0 (Group 18) element inert gas element electron configuration Is22s22p63s23p 3di°4s24p valence state 0 an uncommon valence state +2 exists for its difluoride first ionization potential 13.999 volt six stable natural isotopes are known most abundant isotope Kr-84. Natural isotopes and their abundances Kr-78 (0.354%), Kr-80 (2.20%), Kr-82 (11.56%), Kr-83 (11.55%), Kr-84 (56.90%), Kr-86 (17.37%). 

Symbol Lr atomic number 103 atomic weight 262 a transuranium inner-transition actinide series element a synthetic radioactive element electron configuration [RnjTs b/ Sdi valence +3 six isotopes of masses 255 to 260 have been synthesized longest-lived known isotope Lr-260 has half-life of 3 minutes. 

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. 

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%). 

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%)... 

Symbol Md atomic number 101 atomic weight (most stable isotope) 257 a man-made radioactive transuranium element an inner-transition element of actinide series electron configuration [Rn]5/i37s2 valence +2, -i-3. Isotopes, half-lives and their decay modes are ... 

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. 

---