
Cesium element (Cs) is in group 1 and period 6 of a periodic table. Cesium is in the s-block and it is classified as an alkali metal on the periodic table.
There is a lot more information related to cesium which is mentioned in the Information Table given below.
So let’s dive right into it!
Table of contents
- Cesium element (Information Table)
- Cesium element in Periodic table
- Facts about Cesium
- Properties of Cesium
- Uses of Cesium
Cesium Element (Information Table)
The important data related to cesium element is given in the table below.
Appearance of cesium | Silvery pale golden appearance |
Atomic number of cesium | 55 |
Symbol of cesium | Cs |
Atomic mass of cesium | 132.91 u |
Protons, Neutrons & Electrons in cesium | Protons: 55, Neutrons: 78, Electrons: 55 |
State of cesium (at STP) | Solid |
Group number of cesium in periodic table | 1 |
Period number of cesium in periodic table | 6 |
Block of cesium in periodic table | s-block |
Category of cesium | Alkali metal |
Bohr model or Electrons per shell or Electrons arrangement in cesium | 2, 8, 18, 18, 8, 1 |
Electron configuration of cesium | [Xe] 6s1 |
Orbital diagram of cesium | ![]() |
Valence electron in cesium | 1 |
Electronegativity of cesium (on pauling scale) | 0.79 |
Atomic radius of cesium (van der Waals radius) | 343 picometers |
Density of cesium | 1.88 g/cm3 |
1st ionization energy of cesium | 3.894 eV |
Main isotope of cesium | 133Cs |
Melting point of cesium | 301.7 K or 28.5 °C or 83.3 °F |
Boiling point of cesium | 944 K or 671 °C or 1240 °F |
Crystal structure of cesium | Body Centered Cubic (BCC) |
Discovery of cesium | By Gustav Kirchhoff and Robert Bunsen (in 1860) |
Also see: Interactive Periodic Table (It has rotating bohr models as well as many other details of all the 118 elements in a single periodic table).
Cesium element in Periodic table
The Cesium element (Cs) has the atomic number 55 and is located in group 1 and period 6. Cesium is in solid state at STP and it is classified as an alkali metal on the periodic table.
H | He | ||||||||||||||||
Li | Be | B | C | N | O | F | Ne | ||||||||||
Na | Mg | Al | Si | P | S | Cl | Ar | ||||||||||
K | Ca | Sc | Ti | V | Cr | Mn | Fe | Co | Ni | Cu | Zn | Ga | Ge | As | Se | Br | Kr |
Rb | Sr | Y | Zr | Nb | Mo | Tc | Ru | Rh | Pd | Ag | Cd | In | Sn | Sb | Te | I | Xe |
Cs | Ba | La* | Hf | Ta | W | Re | Os | Ir | Pt | Au | Hg | Tl | Pb | Bi | Po | At | Rn |
Fr | Ra | Ac** | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | Cn | Nh | Fl | Mc | Lv | Ts | Og |
*Ce | Pr | Nd | Pm | Sm | Eu | Gd | Tb | Dy | Ho | Er | Tm | Yb | Lu | ||||
**Th | Pa | U | Np | Pu | Am | Cm | Bk | Cf | Es | Fm | Md | No | Lr |
Facts about cesium
Here are a few interesting facts about cesium.
- Cesium was given its name from the Latin word “caesius”, meaning sky blue.
- Cesium is the 50th most abundant element present in the earth’s crust.
- The concentration of cesium in the earth’s crust is around 3 ppm by weight.
- Bernic lake (in Canada) has the largest deposits of Pollucite (which is an ore of cesium).
- The density of cesium metal is twice the density of water.
Properties of cesium
Here is a list of some physical properties and chemical properties of cesium.
Physical properties of cesium
- Cesium has a silvery pale golden appearance.
- Cesium is ductile and it can be drawn into thin wires.
- Cesium is a very soft metal (just like a wax). Cesium can be cut with a kitchen knife.
- The melting point and boiling point of cesium are 28.5 °C and 671 °C respectively.
- There are many isotopes of cesium and the most abundant isotope is 133Cs.
- Cesium has FCC crystal structure.
Chemical properties of cesium
- Cesium is a very reactive alkali metal and because of this it is always found in compounds with other elements.
- Cesium has 1 valence electron and this electron is lost during a chemical reaction to gain stability.
- Cesium is highly reactive and it is always kept in kerosene or mineral oil to prevent its reaction with air.
- Cesium reacts violently with water and forms cesium hydroxide.
Uses of cesium
Here are some uses of the cesium element.
- Cesium is used in the hydrogenation of organic compounds.
- Cesium is also used in vacuum tubes to remove oxygen gas.
- Some compounds of cesium are also used in the manufacturing of optical glasses.
- Cesium is used in photomultiplier tubes as well as photoelectric cells.
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