Nature is made up of various elements. These elements can be physical, chemical and environmental. The presence of these elements is in various forms and places. A particular element is useful only in a certain form or the other. Therefore, maintaining them in their suitable forms and preventing them from getting damaged or destroyed is of utmost importance. Sodium and Potassium are two such alkali metals found in nature.
Sodium vs Potassium
The main difference between Sodium and Potassium is that Sodium metal is found naturally in oceans in dissolved form, whereas, Potassium metal is found in Earth’s crust in mineral form. Although both these metals are alkaline, i.e. they can form alkaline or basic compounds and also have the same atomic structure, they differ in their atomic number and applications.
Sodium is an alkali metal that is found in dissolved form in oceans. It is chemically denoted by “Na” and has an atomic number of 11. It belongs to the Group 1 elements in the Periodic Table of Chemistry. The metal forms electrovalent bonds with other elements by losing the electron present in its valence shell.
On the other hand, Potassium is present as a mineral in the Earth’s crust. It is chemically denoted by “K”, and its atomic number is 19. It is also specified as alkali metal and belongs to Group 1 elements in the Periodic Table. It contains only one electron in its valence shell. The metal is electrically neutral as it is a pure element.
Comparison Table Between Sodium and Potassium
| Parameters of Comparison | Sodium | Potassium |
| Chemical Symbol | Sodium is an alkali metal which is denoted by “Na”. | Potassium is also an alkali metal denoted by “K”. |
| Atomic Number | Its atomic number is 11. | Its atomic number is 19. |
| Period | It is present in Period 3 in the periodic table. | It is present in Period 4 in the periodic table. |
| Found in | It is found in dissolved form in seawater. | It is found as a mineral in the Earth’s crust. |
| Electronic Configuration | It has an electronic configuration of [Ne] 3s¹. | Its electronic configuration is [Ar] 4s¹. |
| Valence Electron | The valence electron is present in the 3s orbital. | The valence electron is present in the 4s orbital. |
| Melting Point | Its melting point is 97.79°C. | Its melting point is 63.5°C. |
| Boiling Point | Its boiling point is 882.8°C. | Its boiling point is 759°C. |
| Atomic Size | It is smaller in size. | It is comparatively larger than the sodium atom. |
What is Sodium?
Sodium is one of the chemical elements that belong to Group 1 of the periodic table. It is a naturally occurring element that is found dissolved in oceans and seas. In order to bring the metal into a solid form, the method of extraction is used. Sodium has an atomic number of 11. In simpler words, sodium has a total of 11 atoms in its orbitals.
The electronic configuration of sodium is [Ne] 3s¹. The valence electron is present in the 3s orbital. The metal forms strong electrovalent bonds with other elements by losing the valence electron. After losing the electron, Sodium gains a positive charge. It has an atomic mass of around 22.98 amu. It has a shine on its surface, which is called metallic shine.
Sodium has high reactivity. It vigorously reacts with water and oxygen. It is very soft in texture and can be cut with a knife. Therefore, it is usually not preferred as a construction material. Even a tiny amount of sodium reacts readily when added to water. But the same sodium, when reacted with Chloride, forms Sodium chloride or common salt, which is soluble in water.
Sodium forms bonds, which result in the formation of several compounds. Most of the salts of sodium are alkaline. Sodium is also a block element and is able to form a monovalent cation.
What is Potassium?
Potassium is a highly reactive metal that is classified under Period 4 and Group 1 in the periodic table. It is one of the alkali metals, just like sodium. The metal is found naturally as a mineral in the Earth’s crust. Its atomic number is 19, and it is silvery-white in colour.
The electronic configuration of potassium is [Ar] 4s¹. It has the valence electron in the 4s orbital. Potassium loses the valence electron and gains a positive charge. It either forms ionic bonds or anionic compounds by electrostatic attractions. The atomic mass of potassium is around 39.09 amu. Moreover, it is also found as a solubilized ion in seawater.
As potassium is highly reactive, it forms reactive compounds with water and oxygen. It forms hydroxide when water is reacted with it. There are three natural isotopes of potassium, namely potassium-39, potassium-40 and potassium-41. The second and third isotopes are radioactive, and the first one contains an equal number of protons and neurons.
Potassium ion is an essential element for all living beings. Plants use it for photosynthesis. However, the metal should be utilised under a certain limit, or else it can be very toxic.
Main Differences Between Sodium and Potassium
- Sodium is denoted by “Na” while Potassium is denoted by “K”.
- The atomic numbers of Sodium and Potassium are 11 and 19, respectively.
- Sodium is found in oceans and seas, while Potassium is found in Earth’s crust.
- Sodium has higher melting and boiling points than Potassium.
- Potassium is larger than Sodium.
- Sodium belongs to period 3, and Potassium belongs to period 4 on the Periodic Table.
- Sodium forms electrovalent bonds, while Potassium forms ionic bonds with non-metals.
Conclusion
Elements are found in different forms in nature. Some of them are naturally occurring, and some are prepared by humans in the laboratory. The ones that occur naturally are also extracted using various methods as they are usually present in dissolved or solubilized forms.
Sodium and Potassium are two naturally occurring alkali metals. Sodium is extracted from seawater and converted into a solid form. Potassium is obtained by mineral extraction from the Earth’s crust. Both these metals are highly reactive and have a similar atomic structure.
However, they differ in some aspects too. They have different applications and properties. Also, they form different types of bonds with other elements.
References
- https://www.sciencedirect.com/science/article/pii/0002914976903568
- https://www.tandfonline.com/doi/abs/10.1080/07315724.2006.10719576