Electron configurations elements

Ball color Number of holes Identity of element Electron configuration Number of unpaired electrons... 

Symbol Am Atomic Number 95 Atomic Weight 243.0614 an inner-transition, actinide series, radioactive man-made element electron configuration ... 

Symbol Ar atomic number 18 atomic weight 39.948 an inert gas element electronic configuration Is22s22p63s23p ionization potential 15.76eV stable isotopes and natural abundance Ar-40 99.6%, Ar-36 0.337%, Ar-38 0.063% unstable isotopes, half-life and disintegration mode ... 

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 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 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 Es atomic number 99 atomic weight 252 a radioactive transuranium, actinide series, manmade element electron configuration [Rn]5/ i7s2 the most stable isotope Es-254. Isotopes, their half-lives and the mode of decay are as follows ... 

Symbol Fr atomic number 87 atomic weight 223 heaviest adtah metal element of Group lA (Group 1) a radioactive element electron configuration [Rn]7sk oxidation state -i-l the most electropositive element the most stable isotope, Fr-223 (ti/2 21 minutes), also is the only natural isotope. Isotopes, half-lives and their decay modes are shown below ... 

Symbol Gd atomic number 64 atomic weight 157.25 a lanthanide series rare earth element electron configuration 4/ 5di6s2 partially filled / orbital common oxidation state -i-3 six stable natural isotopes Gd-152 (0.2%), Gd-154 (2.86%), Gd-155 (15.61%, Gd-156 (20.59%), Gd-157 (16.42%), Gd-157 (23.45%)... 

Symbol Ga atomic number 31 atomic weight 69.723 a Group lllA (Group 13) element electron configuration [Ar]3di°4s24pi oxidation state -i-3, also exhibits +2 and -i-l ionic radius, Ga + 1.13A two stable natural isotopes Ga-69 (60.20%), Ga-71 (39.80%). 

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 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 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 No atomic number 102 atomic weight 259 an actinide series, transuranium, synthetic radioactive element electron configuration [Rn]5/i47s2 valence states +2, -i-3. 

Symbol Pu atomic number 94 atomic weight 244 an actinide series transuranium element a man-made radioactive element electron configuration [Rn]5/ 7s2 partially filled f suhsheU valence states +3, +4, -i-5, +6 eighteen isotopes in the mass range 228-230, 232-246 aU isotopes radioactive the longest lived isotope Pu-244, ti/2 8.2x10 year the shortest hved isotope Pu-233, ti/2 20.9 minute. 

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. 

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