Analytical testing dots

Lawrencium is a radioactive synthetic element with the symbol Lr (formerly Lw) and atomic number 103. Its most stable isotope is 262Lr, with a half-life of approximately 3.6 hours. Little is known of the chemistry but there is strong evidence for the formation of a trivalent ion in aqueous solution, confirming lawrencium's place as the last member of the actinoids. Although lawrencium is often placed as the last member of the 5f-block, it can also be regarded as the first member of the 6d-block.


Name, Symbol, Number lawrencium, Lr, 103
Chemical series transition metals
Group, Period, Block n/a, 7, d
Appearance unknown, probably silvery
white or metallic gray
Standard atomic weight [262] g·mol-1
Electrons per shell 2, 8, 18, 32, 32, 9, 2
Physical properties
Phase presumably a solid
Melting point -K
(-°C, -°F)
Atomic properties
Oxidation states 3
Electronegativity - (Pauling scale)
Ionization energies 1st: 443.8 kJ/mol
2nd: 1428.0 kJ/mol
3rd: 2219.1 kJ/mol
CAS registry number 22537-19-5


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Analytical testing dots

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