How many electrons does cesium gain or lose
The Correct Answer and Explanation is:
Correct Answer: Cesium loses 1 electron when it forms an ion.
Explanation:
Cesium (Cs) is an element in Group 1 of the periodic table. Elements in this group are known as alkali metals. These metals have one electron in their outermost energy level. For cesium, the electron configuration is:
Cs (Atomic number 55):
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s¹
The outermost electron is in the 6s orbital. Because cesium has a low ionization energy, it easily loses that one outer electron in order to achieve a more stable, noble gas configuration, similar to xenon (Xe).
When cesium loses one electron, it forms a Cs⁺ ion. This ion has 54 electrons (instead of 55), which matches the number of electrons in a xenon atom. Losing an electron allows cesium to reach a stable, full outer energy level, which is a driving force for ion formation.
The ionization of cesium can be written as:
Cs → Cs⁺ + e⁻
The reason cesium prefers to lose rather than gain electrons is based on its atomic structure. Adding electrons to cesium would involve starting to fill a new, higher energy orbital (7s), which is energetically unfavorable. Additionally, cesium’s large atomic size and low effective nuclear charge make it easier for the atom to let go of its one valence electron than to attract additional electrons.
In summary, cesium loses one electron to become a positively charged ion. This makes cesium a typical example of a metal that forms cations. The Cs⁺ ion is commonly found in many compounds and is often used in chemistry and industry due to its reactivity and predictable behavior.
