95 - Americium actinide
Discovered by Glenn Seaborg in 1944
Americium is a radioactive transuranic chemical element with symbol Am and atomic number 95. This member of the actinide series is located in the periodic table under the lanthanide element europium, and thus by analogy was named after the Americas. Americium was first produced in 1944 by the group of Glenn T.Seaborg from Berkeley, California, at the metallurgical laboratory of University of Chicago.
H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
57-71 La-Lu Lanthanides
89-103 Ac-Lr Actinides
| Shell | Electrons | Orbitals |
|---|---|---|
| 1 | 2 | 2 in 1s |
| 2 | 8 | 2 in 2s + 6 in 2p |
| 3 | 18 | 2 in 3s + 6 in 3p + 10 in 3d |
| 4 | 32 | 2 in 4s + 6 in 4p + 10 in 4d + 14 in 4f |
| 5 | 25 | 2 in 5s + 6 in 5p + 10 in 5d + 7 in 5f |
| 6 | 8 | 2 in 6s + 6 in 6p |
| 7 | 2 | 2 in 7s |
silvery white Appearance
243 u Atomic Mass
2.88k K Boiling Point
9 Group
3 Common Oxidation States
1.8 Å Covalent Radius
12 g/cm³ Density
9.93 kJ/mol Electron Affinity
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f7 Electron Configuration
[Rn] 5f7 7s2 Electron Configuration (semantic)
1.3 Electronegativity
95 Electrons
5.97 eV First Ionization Energy
578 kJ/mol Ionization Energies
1.27k K Melting Point
42 Mendeleev Number
62.7 J/(mol·K) Molar Heat
7 Number of Shells
148 Neutrons
95 Atomic Number
133 Number of Isotopes
2, 3, 4, 5, 6 Oxidation States
7 Period
Solid Phase
95 Protons
2, 8, 18, 32, 25, 8, 2 Electron Shell Occupations