Cesium is an alkali metal with an atomic mass of 132.9, and the chemical symbol is Cs. Let us study its electronegativity and ionization energy properties in detail.
The electronegativity value of cesium is 0.79 in Pauling scale. Cesium belongs to the s-block of the periodic table. Its chemical properties are similar to those of potassium and rubidium.
All the significant aspects of electronegativity and ionization energy of cesium will come to light as we proceed.
Cesium ionization energy
The atomic number of cesium is 55 and the electron configuration is [Xe]6s1.
- The first ionization energy of cesium is 375.70 kJ/mole, which is required to remove the only valence electron from 6s orbital.
- The second ionization energy of cesium is 2234.35 kJ/mole, which is required to remove an electron from 5p orbital.
Cesium and sodium ionization energy
The electronic configuration of cesium and sodium is [Xe]6s1 and [Ne]3s1, respectively. Both elements are from the same group and sodium belongs to the third period whereas cesium belongs sixth period. A comparison of their ionization energy is shown below.
| First ionization energy of Cesium | First ionization energy of Sodium | Explanation |
|---|---|---|
| 375.70 kJ/mole | 495.85 kJ/mole | The value is higher for sodium compared to cesium as normally down the group, ionization energy value decreases as atomic size increases. |
Cesium and rubidium ionization energy
The electronic configuration of cesium and rubidium is [Xe]6s1 and [Kr]5s1, respectively. Both elements are from the same group and rubidium belongs to fifth period whereas cesium belongs to sixth period. A comparison of their ionization energy is shown below.
| First ionization energy of Cesium | First ionization energy of Rubidium | Explanation |
|---|---|---|
| 375.70 kJ/mole | 403.03 kJ/mole | The value is higher for rubidium compared to cesium as rubidium is just above cesium in the same group. Normally down the group ionization energy value decreases as atomic size increases. |
Cesium and francium ionization energy
The electronic configuration of cesium and francium is [Xe]6s1 and [Rn]7s1, respectively. Both elements are from the same group and francium belongs to seventh period whereas cesium belongs to sixth period. A comparison of their ionization energy is shown below.
| First ionization energy of Cesium | First ionization energy of Francium | Explanation |
|---|---|---|
| 375.70 kJ/mole | 392.96 kJ/mole | The value is higher for francium though francium is just below cesium. Normally, down the group, ionization energy value decreases but here reverse is occurring because of the relativistic effect. |
Cesium electronegativity
The electronegativity value of cesium is 0.79 in Pauling scale. The value is not very high because of its metallic nature.
Sulfur and cesium electronegativity
The value of electronegativity of sulfur and cesium highly differ from each other as sulfur is a non-metal and cesium is a metal. A comparison of their electronegativity values is shown below.
| Electronegativity value of Sulphur | Electronegativity value of Cesium | Explanation |
|---|---|---|
| 2.58 in Pauling scale | 0.79 in Pauling scale | The electronegativity value of sulfur is higher than cesium as electronegativity values are higher for non-metals than that for metals. |
Electronegativity of cesium and francium
The electronegativity values of cesium and francium do not highly differ from each other as both are metals. A comparison of their electronegativity values is shown below.
| Electronegativity value of Cesium | Electronegativity value of Francium | Explanation |
|---|---|---|
| 0.79 in Pauling scale | 0.70 in Pauling scale | The electronegativity value of cesium is higher than that of francium as down the group electronegativity decreases as metallic nature increases. Both elements are from the same group and francium is just below cesium. |
Conclusion
In conclusion, cesium should be stored in sealed containers, under an inert liquid or gas, or in a vacuum because of its reactive nature. The only stable isotope of cesium that occurs naturally is cesium-133. One of the most important applications of this metal is the ‘cesium clock’ (atomic clock).
Hello, I am Tuluma Das, Completed my Ph.D. in Organic Chemistry from the Indian Association for the Cultivation of Science. I have a total of 9 years of research experience including a Ph.D. and Postdoc and 3 years of teaching experience. I have published 7 papers so far in international journals. Let’s connect through Linkedin :