95 predicted 2 · 8 · 18 · 32 · 25 · 8 · 2

Americium, Am, element 95

Actinide· Period 7· f-block

Configuration [Rn]5f77s2

Atomic weight
243Da
Phase
solid
Density
12g/cm³
Melting point
1,449.15K 1,176 °C
Boiling point
2,880K, predicted 2,607 °C
Electronegativity
1.3

Radioactive metallic transuranic element, belongs to the actinoids. Ten known isotopes. Am-243 is the most stable isotope, with a half-life of 7.95*10^3 years. Discovered by Glenn T. Seaborg and associates in 1945, it was obtained by bombarding Uranium-238 with alpha particles. Description from mendeleev.

Back to the table
The outermost shell: the valence electronsThe inner shellsThe nucleus One bead for each electron, on the ring of its shell, counted from the nucleus out. The rings turn at their own pace; the model is Bohr's picture of the atom, which places electrons in shells but not on true orbits.

Atomic properties

4 of 5 fields have a value for americium

Atomic weight The standard atomic weight. For an element with no stable isotope, the mass of its longest-lived isotope.
243Da
Source: mendeleev
Electron configuration
[Rn]5f77s2
Source: mendeleev
Electron configuration in full The electron configuration with the noble-gas core written out.
1s22s22p63s23p63d104s24p64d104f145s25p65d105f76s26p67s2
Source: Worked outfrom electron configuration
Electrons in each shell Counted from the electron configuration, from the first shell outward.
2 · 8 · 18 · 32 · 25 · 8 · 2
Source: Worked outfrom electron configuration

No data uncertainty of the atomic weight.