87
Fr
223
Francium
Alkali Metal
Group 1
Period 7
Block s
Francium is a chemical element of the periodic table with chemical symbol Fr and atomic number 87 with an atomic weight of 223 u and is classed as alkali metal and is part of group 1 (alkali metal). Francium is solid at room temperature.
Francium in the periodic table
| Symbol | Fr |
| Atomic number | 87 |
| Group | 1 (Alkali metal) |
| Period | 7 |
| Block | s |
| Classification | Alkali Metal |
| Appearance | - |
| Color | Silver |
| Number of protons | 87 p+ |
| Number of neutrons | 136 n0 |
| Number of electrons | 87 e- |
From Wikipedia, the free encyclopediaFrancium is a chemical element with symbol Fr and atomic number 87. It used to be known as eka-caesium and actinium K. It is the second-least electronegative element, behind only caesium. Francium is a highly radioactive metal that decays into astatine, radium, and radon.
Physical properties
| Phase at STP | Solid |
| Density | 1.87 g/cm3 |
| Atomic weight | 223 u |
Thermal properties
| Melting point | 300 K 26.85 °C 80.33 °F |
| Boiling point | 950 K 676.85 °C 1250.33 °F |
| Heat of vaporization | 64 kJ/mol |
Atomic properties
| Electronegativity (Pauling Scale) | 0.79 |
| Electron affinity | 46.89 kJ/mol |
| Oxidation states | +1 (a strongly basic oxide) |
| Ionization energies |
|
Electron configuration for francium
Electron configuration Shorthand configuration | [Rn] 7s1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Full configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s24p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 7s1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Electron configuration chart |
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Electrons per shell | 2, 8, 18, 32, 18, 8, 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Valence electrons | 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Valency electrons | 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bohr model | Figure: Shell diagram of Francium (Fr) atom. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Orbital Diagram
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The history of Francium
| Discovery and first isolation | Marguerite Perey (1939) |
Discovery of francium Francium was discovered by Marguerite Perey in France (from which the element takes its name) in 1939. Prior to its discovery, it was referred to as eka-caesium or ekacaesium because of its conjectured existence below caesium in the periodic table. It was the last element discovered in nature, rather than synthesized, following hafnium and rhenium. Perey named the new isotope actinium-K (it is now referred to as francium-223) and in 1946, she proposed the name catium (Cm) for her newly discovered element, as she believed it to be the most electropositive cation of the elements. Irène Joliot-Curie, one of Perey's supervisors, opposed the name due to its connotation of cat rather than cation; furthermore, the symbol coincided with that which had since been assigned to curium. Perey then suggested francium, after France. This name was officially adopted by the International Union of Pure and Applied Chemistry (IUPAC) in 1949, becoming the second element after gallium to be named after France. It was assigned the symbol Fa, but this abbreviation was revised to the current Fr shortly thereafter. | |
| Original word | Francia |
| Language of origin | Latin |
| Name source | Place |
| Meaning | “France” |
| Country | France |
Naming The element is named after France, the home country of its discoverer Marguerite Perey, who identified it at the Curie Institute in Paris. | |