93 - Neptunium actinide
Discovered by Edwin McMillan in 1940
Neptunium is a chemical element with symbol Np and atomic number 93. A radioactive actinide metal, neptunium is the first transuranic element. Its position in the periodic table just after uranium, named after the planet Uranus, led to it being named after Neptune, the next planet beyond Uranus.
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 | 22 | 2 in 5s + 6 in 5p + 10 in 5d + 4 in 5f |
| 6 | 9 | 2 in 6s + 6 in 6p + 1 in 6d |
| 7 | 2 | 2 in 7s |
silvery metallic Appearance
237 u Atomic Mass
4.27k K Boiling Point
7 Group
5 Common Oxidation States
1.9 Å Covalent Radius
20.4 g/cm³ Density
45.9 kJ/mol Electron Affinity
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f4 6d1 Electron Configuration
[Rn] 5f4 6d1 7s2 Electron Configuration (semantic)
1.36 Electronegativity
93 Electrons
6.27 eV First Ionization Energy
604.5 kJ/mol Ionization Energies
913 K Melting Point
44 Mendeleev Number
29.5 J/(mol·K) Molar Heat
7 Number of Shells
144 Neutrons
93 Atomic Number
153 Number of Isotopes
3, 4, 5, 6, 7 Oxidation States
7 Period
Solid Phase
93 Protons
2, 8, 18, 32, 22, 9, 2 Electron Shell Occupations