Difference Between Sodium and Potassium

Sodium vs Potassium

Sodium and Potassium are naturally occurring alkaline metals that show many similarities in their behaviors. Both sodium and potassium ions are essential for all life forms. Both ions are highly reactive and easily dissolve in water which is why both are found more in seawater than on land. Both sodium and potassium are also found as parts of various minerals. However, there are many differences in these two substances depending upon their properties as also upon their requirements in our bodies. Let us take a closer look.

Despite being a metal, sodium is very soft and one can cut it using a knife at room temperature. It has a bright silvery luster. One surprising fact is that though density of substances increase with an increase in their atomic number, Sodium is denser than Potassium even though the atomic number of sodium is only 11 while that of potassium is 19. Alkali metals are known to be reactive, but sodium is less reactive than potassium. Sodium makes many important compounds widely used in industries such as Baking soda, soda ash, common salt, sodium nitrate, borax and caustic soda.

Potassium reacts with water producing hydrogen. Sodium also produces hydrogen when reacting with water but the reaction of potassium with water is much more violent. Because of their high reactivity, both Sodium and potassium are found in the form of their compounds only. While sodium is the 6th most abundant material in earth’s crust, potassium is the most abundant material.

Talking about human beings, though both sodium and potassium ions are required by us, they must have a balance, as excess of either result in ailments. There is a common perception that high amounts of sodium in our bodies, consumed through common salt results in hypertension, heart disease and diabetes.

While sodium ion is found mostly in fluids outside cells in our bodies, potassium ion is found mostly inside the cells in fluids. Some sodium is found inside cell membranes while some potassium is found outside the cells also. There is a delicate balance in the concentration of sodium and potassium ions across cell membrane that needs to be maintained by us. But it has been seen that our diet contains more of sodium than potassium with the result that this delicate balance is disturbed. This imbalance leads top many ailments of heart and blood pressure. When potassium levels go dangerously low in human bodies, they lead to several disorders such as lung and kidney disorders, and hypertension which has become a common problem across all cultures of the world.

So while we are advised by doctors to reduce our intake of sodium through diet, it is important to increase the intake of potassium to reach a balance between the two essential metals inside our bodies.

In brief:

Potassium vs Sodium

• Sodium has an atomic number of 11 while potassium has an atomic number of 19

• Despite smaller atomic number, sodium is denser than potassium

• Potassium reacts much more violently with water

• While excess of sodium is harmful for us, low levels of potassium have also been found to be associated with certain disorders of lungs and heart.