87 Fr Francium 223,0 u

Francium

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Период
7
Группа
1
Блок
s-Блок
Фаза (СТУ)
Solid

Francium is the most unstable of the first 101 elements. It is extremely rare in nature, with at most 30 grams in Earth's crust at any time.

About Francium

Of the first 101 elements, none is more unstable than francium. Its nuclei decay so quickly that no more than about 30 grams are present in the crust at any moment, sustained entirely by the decay of heavier actinides. The element holds atomic number 87 and a relative atomic mass of 223.0, and the single valence electron of its [Rn] 7s1 configuration makes it the heaviest alkali metal in group 1 of period 7. Its Pauling electronegativity of 0.7 is the lowest assigned to any element, a direct consequence of how weakly that outermost s electron is held. Francium is a solid at standard conditions, though bulk samples have never been isolated in a quantity sufficient to examine directly.

Физические свойства

Атомная масса 223.0 u
Фаза при СТУ Solid

Электронные свойства

Электроотрицательность 0.7

Электронная конфигурация

Конфигурация [Rn] 7s¹

Electron Shell Configuration

Francium electron shell configuration Fr 2e⁻ 8e⁻ 18e⁻ 32e⁻ 18e⁻ 8e⁻ 1e⁻
Electron shell structure of Francium — electrons per shell.
Shell Electrons
1 (K) 2
2 (L) 8
3 (M) 18
4 (N) 32
5 (O) 18
6 (P) 8
7 (Q) 1

Position in Periodic Table

Francium position in the periodic table Fr

Блок и период

Блок

s p d f

Период

1 2 3 4 5 6 7

Периодическая таблица

Лантаниды Актиниды

Больше Щелочной металл

3 Li Lithium 11 Na Sodium 19 K Potassium 37 Rb Rubidium 55 Cs Cesium

Frequently Asked Questions

What is Francium?
Francium (Fr) is a chemical element with atomic number 87. It is a solid at standard temperature and pressure, classified as a щелочной металл.
What are the key properties of Francium?
Francium has an atomic mass of 223.0 u.
What is the electron configuration of Francium?
The electron configuration of Francium is [Rn] 7s1. It is in the s-block of the periodic table.
What is the electronegativity of Francium?
Francium has an electronegativity of 0.7 on the Pauling scale.