fermium

fermium (chemical element)

Periodic table location

atomic symbol | Fm atomic number | 100 short electronic configuration | [Rn]7s^25f^12 Aufbau diagram | 5f 7s block | f period | 7 atomic mass | 257 u (unified atomic mass units) (atomic mass number given for longest-lived known isotope) half-life | 100.5 days

melting point | 1527 °C (rank: 27th) (properties at standard conditions)

valence | 3 electronegativity | 1.3 first ionization energy | 627 kJ/mol (kilojoules per mole) ionization energies | 627 kJ/mol

term symbol | ^3H_6 (electronic ground state properties)

solar abundance | 0 mass% meteorite abundance | 0 mass% crust abundance | 0 mass% ocean abundance | 0 mass% human abundance | 0 mass% solar molar abundance | 0 mol% meteorite molar abundance | 0 mol% ocean molar abundance | 0 mol% crust molar abundance | 0 mol% human molar abundance | 0 mol%

half-life | 100.5 days lifetime | 145 days (rank: 1st) specific radioactivity | 187 TBq/g decay mode | alpha emission nuclear spin | Fm-242: 0^+ | Fm-243: 7/2^+ | Fm-244: 0^+ | Fm-245: 1/2^+ | Fm-246: 0^+ | Fm-247: 7/2^+ | Fm-248: 0^+ | Fm-249: 7/2^+ | Fm-250: 0^+ | Fm-251: 9/2^- | Fm-252: 0^+ | Fm-253: 1/2^+ | Fm-254: 0^+ | Fm-255: 7/2^+ | Fm-256: 0^+ | Fm-257: 9/2^+ | Fm-258: 0^+ | Fm-259: 3/2^+ | Fm-260: 0^+ unstable isotopes | Fm-257 (100.5 days) | Fm-253 (72 h) | Fm-252 (25.4 h) | Fm-255 (20.069 h) | Fm-251 (5.3 h) | Fm-254 (194.4 min) | Fm-256 (157.6 min) | Fm-250 (30 min) | Fm-249 (160 s) | Fm-248 (36 s) | Fm-247 (29 s) | Fm-245 (4.2 s) | Fm-259 (1.5 s) | Fm-246 (1.1 s) | Fm-243 (180 ms) | Fm-260 (4 ms) | Fm-244 (3.3 ms) | Fm-242 (800 µs) | Fm-258 (370 µs) neutron cross-section | 5800 b

CAS number | 7440-72-4 PubChem CID number | 23998