Element Information, Facts, Properties, Trends, Uses, Comparison with other elements
Francium 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.
It belongs to group 1 of the periodic table having trivial name alkali metals*. Hydrogen resides within this column, but is not considered an alkali metal.
Read key information and facts about element Francium
|Group in Periodic Table||1|
|Group Name||lithium family|
|Period in Periodic Table||period 7|
|Block in Periodic Table||s -block|
|Electronic Configuration||[Rn] 7s1|
|Electronic Shell Structure (Electrons per shell)||2, 8, 18, 32, 18, 8, 1|
|Melting Point||281 K|
How to Locate Francium on Periodic Table
Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 87 to find Francium on periodic table.
Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Francium on periodic table look for cross section of group 1 and period 7 in the modern periodic table.
The element Francium was discovered by M. Perey in year 1939 in France. Francium was first isolated by in . Francium derived its name from Francia, the New Latin name for France.
Perey discovered it as a decay product of 227Ac. Francium was the last element to be discovered in nature, rather than synthesized in the lab, although four of the "synthetic" elements that were discovered later (plutonium, neptunium, astatine, and promethium) were eventually found in trace amounts in nature as well.
Francium Presence: Abundance in Nature and Around Us
The table below shows the abundance of Francium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.
|ppb by weight (1ppb =10^-7 %)||ppb by atoms (1ppb =10^-7 %)|
|Abundance in Universe||-||-|
|Abundance in Sun||-||-|
|Abundance in Meteorites||-||-|
|Abundance in Earth's Crust||-||-|
|Abundance in Oceans||-||-|
|Abundance in Humans||-||-|
Crystal Structure of Francium
The solid state structure of Francium is Body Centered Cubic.
The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.
Unit Cell Parameters
The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)
and the angles between them Lattice Angles (alpha, beta and gamma).
The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.
The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.
|Space Group Name||-|
|Oxidation States||Space Group Number||-|
|Crystal Structure||Body Centered Cubic|
Francium Atomic and Orbital Properties
Francium atoms have 87 electrons and the electronic shell structure is [2, 8, 18, 32, 18, 8, 1] with Atomic Term Symbol (Quantum Numbers) 2S1/2.
|Number of Electrons (with no charge)||87|
|Number of Protons||87|
|Number of Neutrons||136|
|Shell structure (Electrons per energy level)||2, 8, 18, 32, 18, 8, 1|
|Electron Configuration||[Rn] 7s1|
|Main Oxidation States||1|
|Atomic Term Symbol (Quantum Numbers)||2S1/2|
Bohr Atomic Model of Francium - Electrons per energy level
Ground State Electronic Configuration of Francium - neutral Francium atom
Abbreviated electronic configuration of Francium
The ground state abbreviated electronic configuration of Neutral Francium atom is [Rn] 7s1. The portion of Francium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Rn]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 7s1, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Francium
Complete ground state electronic configuration for the Francium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p6 7s1
Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.
Atomic Structure of Francium
Francium atomic radius is - , while it's covalent radius is - .
|Atomic Radius Calculated|
- (0 Å)
|Atomic Radius Empirical|
- (0 Å)
|Van der Waals Radius||348 pm|
|Neutron Cross Section||-|
|Neutron Mass Absorption||-|
Atomic Spectrum of Francium
Francium Chemical Properties: Francium Ionization Energies and electron affinity
The electron affinity of Francium is - .
Ionization Energy of Francium
Refer to table below for Ionization energies of Francium
|Ionization energy number||Enthalpy - kJ/mol|
Francium Physical Properties
Refer to below table for Francium Physical Properties
Hardness of Francium - Tests to Measure of Hardness of Element
Francium Electrical Properties
Francium is Conductor of electricity. Refer to table below for the Electrical properties ofFrancium
Francium Heat and Conduction Properties
Francium Magnetic Properties
|Mass Magnetic Susceptibility||-|
|Molar Magnetic Susceptibility||-|
|Volume Magnetic Susceptibility||-|
Optical Properties of Francium
Acoustic Properties of Francium
|Speed of Sound||-|
Francium Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Francium
|Melting Point||281 K (7.85°C, 46.13000000000004 °F)|
|Boiling Point||- (-273.15°C, -459.66999999999996 °F)|
Enthalpies of Francium
|Heat of Fusion||2 kJ/mol|
|Heat of Vaporization||65 kJ/mol|
|Heat of Combustion||-|
Francium Isotopes - Nuclear Properties of Francium
Francium has 34 isotopes, with between 199 and 232 nucleons. Francium has 0 stable naturally occuring isotopes.
Isotopes of Francium - Naturally occurring stable Isotopes: -.
|Isotope||Z||N||Isotope Mass||% Abundance||T half||Decay Mode|