Nobelium (symbol No, atomic number 102) is a synthetic actinide named after Alfred Nobel. It is classified as a actinide and sits in the actinide series (f-block), period 7 of the periodic table.
Overview
Nobelium is the chemical element with atomic number 102 and the symbol No. With a standard atomic weight of [259], it is a actinide. In the periodic table it occupies the actinide series (f-block) and period 7, and under standard conditions it is normally a solid. Nobelium is a synthetic actinide named after Alfred Nobel.
Atomic structure
An atom of Nobelium has 102 protons in its nucleus and, when neutral, 102 electrons arranged in the configuration [Rn] 5f14 7s2. Nobelium has no stable isotope; the value [259] refers to the mass number of its most stable or most commonly produced isotope.
Discovery and place in the table
Nobelium was discovered in 1966 by Joint Institute for Nuclear Research. It follows Mendelevium (Md) and precedes Lawrencium (Lr) in order of atomic number.
| Atomic number | 102 |
|---|---|
| Symbol | No |
| Atomic mass | [259] |
| Category | Actinide |
| Group | — |
| Period | 7 |
| Electron configuration | [Rn] 5f14 7s2 |
| Phase at STP | Solid |
| Discovered | 1966 (Joint Institute for Nuclear Research) |