The charge of an element could be referring to its ionic charge, its nuclear charge, or its effective nuclear charge (Zeff). One of the ways to determine the charge of an element is to trace it to its position on the periodic table. The group it belongs to can be your first guess of the ionic charge.
Also, the number of electrons the atom loses or gains also determines the charge. The case study of this article is cesium. And, I will discuss its charge using these factors and others. You will also learn about the reactions cesium will naturally undergo.
Properties of cesium
- Cesium is an alkali metal located in group 1, period 6 of the periodic table
- Cesium has atomic number 55 and mass number 132.9
- At STP, it is a pale gold soft metal with a melting point of 83.3°F (28.5°C) and boiling point of 1,240°F (671°C)
- At its melting point, cesium has a density of 1.843 g/cm3. The density increases to 1.93 g/cm3 when it is near room temperature
- Cesium is a rare element. It is the 45th most abundant element and 36th most abundant metal on the Earth’s crust. The quantity of cesium on the earth is estimated at 7 parts per million (ppm)
- Cesium does not occur by itself. It is usually found in combination with other metals, such as rubidium
- It also exists in minerals like pollucite, rhodizite, and lepidolite
- Pure cesium can only be gotten through the reduction of cesium salts with sodium metal and by electrolysis of a molten cesium cyanide/barium cyanide mixture
- Furthermore, cesium has an electronic configuration of 1s22s22p63s23p63d104s24p64d105s25p66s1 with 2, 8, 18, 18, 8, 1 electrons in its shells
- Cesium is always in its +1 oxidation state. But, it can also be in a -1 oxidation state (this is very rare)
- This is the least electronegative element on the Pauling scale. Its electronegativity value is 0.79
- In addition, the first, second, and third ionization energies of cesium are 375.7 kJ/mol, 2,234.3 kJ/, and 3,400 kJ/mol
What is the ionic charge of cesium?
When cesium forms an ion, it gets a +1 charge and becomes Cs+. As a metal, Cs will form ions by losing the single electron in its valence shell electron. This election loss usually happens when the metal reacts with nonmetals.
Also, you can see that as a group one metal, it has a valency of 1, an oxidation state of +1, and a charge of +1.
What is the charge of cesium in cesium monoxide?
To determine the charge of cesium in cesium monoxide, Cs2O, substitute the charge of O, which is -2, into the chemical formula and equate it to the overall charge of the compound.
2Cs + (-2) = 0
2Cs = +2
Cs = +1
What is the charge of cesium in cesium chloride?
In cesium chloride, CsCl, Cs is the cation and Cl is the anion. Cl has a -1 charge and we can put this value into the chemical formula to determine the charge of Cs.
Cs + (-1) = 0
Cs = +1
What is the charge of cesium in cesium bisulfate?
In Cesium bisulfate, CsHSO4, Cs has a +1 charge.
HSO4 has a -1 charge. If you substitute this value into the chemical formula, the equation will be:
Cs + (-1) = 0
Cs = -1
What is the Zeff of cesium?
You can determine the Zeff of cesium with the formula:
Zeff = Z – S
Z is the nuclear charge. It is equal to 55
S is the shielding constant which will be determined using Slater’s rule
We will start with writing out the electronic configuration of cesium: 1s22s22p63s23p63d104s24p64d105s25p66s1
All electrons in orbitals 1s22s22p63s23p63d104s24p64d10 experience a shielding constant of 1. The total number of electrons is 46
Electrons in orbitals 5s25p6 experience a shielding constant of 0.85, and the total number of electrons is 8
The electron in orbital 6s1 experiences a shielding constant of 0.35. This is the electron of concern, so its number is neglected
S = (46 x 1) + (8 x 0.85) + (0 x 0.85)
S = 52.8
Zeff = Z – S
Zeff = 55 – 52.8 = 2.2
What are the reactions of cesium?
Cesium undergoes the likely reactions other alkali metals undergo. They are as follows:
Reaction with water
Cesium reacts violently with water, producing cesium hydroxide (CsOH) and hydrogen gas (H2). It is a highly exothermic reaction, and there can be explosions sometimes.
2Cs + 2H2O → 2CsOH + H2
Reaction with oxygen
When cesium reacts with oxygen in the air, it forms cesium oxide (Cs2O) and cesium superoxide (CsO2) as it reacts further.
4Cs + O2 → 2Cs2O
4Cs + 2O2 → 2CsO2
Reaction with halogens
Cesium forms cesium halides when it reacts with halogens (fluorine, chlorine, bromine, iodine). The reactions with some halogens are as follows:
- 2Cs + Cl2 → 2CsCl
- 2Cs + Br2 → 2CsBr
- 2Cs + I2 → 2CsI
Reaction with acids
When cesium reacts with acids, it produces cesium salts and releases hydrogen gas. You can see this reaction in the equation below:
2Cs + 2HCl → 2CsCl + H2
Reaction with sulfur
Cesium forms cesium sulfide when it reacts with sulfur. The reaction is as follows:
4Cs + S8 → 4Cs2S
Reaction with nitrogen
When cesium reacts with nitrogen, it forms cesium nitride (Cs3N) as seen in the reaction below:
6Cs + N2 → 2Cs3N
Reaction with alkynes
The alkyne family are organic compounds with C-C triple bonds. When cesium reacts with these compounds, it forms alkynides salts that contain the C≡C⁻ anion.
2Cs + C2H2 → 2CsC2H
Reaction with organic compounds
Cesium reacts with some organic compounds just like other alkali metals do. It will displace hydrogen atoms in hydrocarbons to form alkylated derivatives.
FAQs
What is the nuclear charge of cesium?
The nuclear charge of cesium is equal to its atomic number, which is 55.
How many isotopes of cesium are there?
Cesium has 40 known isotopes. They range from Cs-112 to Cs-151, with Cs-133 being the most stable. Except for three isotopes, Cs-134, Cs-135 & Cs-137, cesium isotopes have short half-lives (between one hour and two weeks).
Cs-134 has a half-life of 2.0652 years, Cs-135 has a half-life of 2.3 million years, and Cs-137 has a half-life of 30.1671 years.
How many protons are in Cs+?
Cs+ has 55 protons like the neutral Cs atom.
Ions retain their number of protons and neutrons. The number of electrons may be more or less, depending on how the atom reacts. But, in the case of cesium, the number of electrons is less by one because it loses an electron to form Cs+.
Conclusion
Cesium has one electron in its valence shell and will lose this electron when it reacts with other elements. This results in the formation of Cs+. The charge of cesium is the same as its oxidation state and valency.
Cesium is a unique alkali metal. It is the most electropositive in its group. Moreover, its +1 charge makes it highly unstable. The metal can easily gain the electron again from another element and form an atom. However, it is a very reactive metal and forms strong ionic bonds with nonmetals.
Learn about the charge of potassium, another alkali metal.
Thanks for reading.