Monazite is cracked with hot NaOH or H2SO4; Th is separated from rare earths and from U by solvent extraction, and ThO2 is reduced with Ca metal to Th sponge.
Research Elements Th · atomic number 90 Actinide · period 7 [Rn] 6d2 7s2 Shells: 2, 8, 18, 32, 18, 10, 2 Valence electrons: 2 in the outer shell (7s2), and 2 in 6d2 Green dots are the outer shell's s and p electrons. Softer green dots are the d electrons of transition metals, and the d and f electrons of lanthanides and actinides: they often take part in bonding, but not always. Grey dots are the core. Ground-state configuration from the NIST Atomic Spectra Database (A. Kramida, Yu. Ralchenko, J. Reader and the NIST ASD Team). Abundance is the mole fraction of the element found as that isotope on Earth; digits in parentheses are the uncertainty in the last digits. Masses and abundances from NIST, Atomic Weights and Isotopic Compositions (J. S. Coursey, D. J. Schwab, J. J. Tsai and R. A. Dragoset, National Institute of Standards and Technology).Thorium
Electrons
How it's obtained
Natural isotopes
Isotope Relative atomic mass Abundance 232Th 232.0380558(21) 1