78 - Platinum transition metal
Discovered by Antonio de Ulloa in 1735
Platinum is a chemical element with symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, gray-white transition metal. Its name is derived from the Spanish term platina, which is literally translated into "little silver".
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 | 17 | 2 in 5s + 6 in 5p + 9 in 5d |
| 6 | 1 | 1 in 6s |
195 u Atomic Mass
1.8 Å Atomic Radius
4.1k K Boiling Point
1.36 Å Covalent Radius
21.4 g/cm³ Density
205 Electron Affinity
2.28 Electronegativity
8.96 eV First Ionization Energy
2.05k K Melting Point
6 Number of Shells
78 Atomic Number
2, 8, 18, 32, 17, 1 Electron Shell Occupations