88 - Radium alkaline earth metal
Discovered by Pierre Curie in 1898
Radium is a chemical element with symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is almost colorless, but it readily combines with nitrogen (rather than oxygen) on exposure to air, forming a black surface layer of radium nitride (Ra3N2).
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 | 18 | 2 in 5s + 6 in 5p + 10 in 5d |
6 | 8 | 2 in 6s + 6 in 6p |
7 | 2 | 2 in 7s |
226 u Atomic Mass
2.01k K Boiling Point
2.21 Å Covalent Radius
5.5 g/cm³ Density
9.65 Electron Affinity
0.9 Electronegativity
5.28 eV First Ionization Energy
973 K Melting Point
7 Number of Shells
2 Electron Valency
88 Atomic Number
2, 8, 18, 32, 18, 8, 2 Electron Shell Occupations