Tableau périodique

Américium (Am)

Américium is the chemical element with atomic number 95 and symbol Am. It is a actinide in period 7, with a standard atomic weight of 243 u.

Faits essentiels

Z
95
Atomic weight
243 u no stable isotope
Category
actinide
State at 298 K
Solid
Occurrence
synthetic, radioactive
Discovered
1944
CAS
7440-35-9

Propriétés mesurées

PropertyValueSource
Electronegativity 1.3 National Center for Biotechnology Information (NIH)
Melting point 1,449 K National Center for Biotechnology Information (NIH)
Boiling point 2,284 K National Center for Biotechnology Information (NIH)
Density stp 13.69 g/cm³ National Center for Biotechnology Information (NIH)
Atomic radius empirical 244 pm National Center for Biotechnology Information (NIH)
Ionization energy 1st 578.2 kJ/mol National Center for Biotechnology Information (NIH)

Configuration électronique

2 8 18 32 25 8 2 Am
Noble gas notation
[Rn] 5f⁷ 7s²
Full notation
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 5f⁷ 6s² 6p⁶ 7s²
Electrons per shell
2, 8, 18, 32, 25, 8, 2

Isotopes

Sources