How many atoms in a grain of salt?

In this brief guide, we are going to answer the question “How many atoms in a grain of salt?”, discuss answers to other related questions like how long does salt last and does salt expire.

How many atoms in a grain of salt?

It is quite difficult to tell the atoms in a grain of salt as there is no exact measure of how big a ‘grain of salt’ is. So, the answer will be only correct within an order of magnitude (a factor of 10)!

The first step is to estimate how large a grain of salt is? So let’s assume that salt grains are 0.3 millimeters long. The density of NaCl is about 2.165 grams per centimeter cube. With the cube assumption, a grain of salt is about 5.85×10^-5 grams. The next thing we need is the weight of a ‘salt atom’. By heading towards the average values, the atomic mass of Na is 23 g/mol, and the atomic mass of Cl is 35.5 g/mol. So, the average ‘atomic weight of salt’ is 29.25 g/mol. So a grain of salt contains about:

5.85×10-5 gr/ (29.25 gr / 6.02×10^23) = 1.2×10^18 atoms, half of which are sodium atoms and the other half is chlorine atoms, of course.

How long does salt last?

Salt, chemically defined as Sodium Chloride, can last indefinitely unless it has additives in it. Salt is used in preservation by depriving the food product of its moisture (Microbes need moisture for growth).

But the commercially packaged salt is rarely pure. Unrefined or unprocessed sea salt has traces of algal products (WIKI:S), iodized salt or table salt contains iodine (WIKI: IS), and the pin Himalayan salt’s color is due to mineral impurities (WIKI: HS). These additives (iodine and algae) have a limited shelf life.

Despite the limited shelf-life of these additives, they do not spoil the salt. However, the salt loses its strength and nutrients if it is way past-by its best-by date.

The iodized salt that is long past its date loses iodine content. If you are using salt for iodine, such salt is of no use.

How to store salt?

For storing salt, treat it like other spices like chili powder and pepper. The rule of thumb is to store any type of salt in a cool and dry place in a well-sealed container to protect it from unwanted flavors. Keep the salt in a cabinet to protect it from picking up unwanted odors.

An unopened salt package can be stored in the pantry. An opened package is best kept in the kitchen. It is recommended to transfer some of the salt into a resealable salt container or shaker and store the rest of the salt separately.

Iodized salt must be stored away from heat or else it will lose all of its iodine content gradually. Using an air-tight container for keeping salt is important to prevent clumping which results due to the hygroscopic nature of the salt.

Does salt expire?

Salt does not expire because it is inherently anti-bacterial and moisture-free. However, the additives, like iodine, present in salt can develop some undesirable changes in the flavor and texture of salt over time. But if you have stored it properly, it can last for an indefinite time duration.

Iodized salt

Iodized or table salt is a highly processed salt. It is deprived of most of the nutrients due to processing. To prevent it from clumping, additives like anticaking and iodine are added to salt during processing. The iodine in the salt limits its shelf life to 5 years only.

Kosher salt

Kosher salt does not contain iodine. The coarse texture of kosher salt is particularly helpful in extracting blood from the meat. Also, it has a different flavor than that of table salt. For peak quality, it is recommended to use kosher salt within 5 years. However, the salt can remain safe to use beyond this time frame.

Himalayan salt

As compared to table salt, Himalayan salt contains 84 essential minerals that the table salt lacks. This type of salt has great health benefits and is mined in Pakistan. Himalayan salt has less sodium and more potassium, magnesium, iron, and calcium.

Himalayan salt has natural iodine and iron oxide. It may also have some added iodine. The Himalayan salt block will have to be thrown if it has been frequently in contact with oil, heat, or coarse surfaces.

Sea salt

Unlike table salt, sea salt does not have additives like iodine. Sea salt is prepared by evaporating seawater and might contain trace minerals and trace impurities. Sea salt has a coarser texture and a stronger flavor than traditional salt. Sea salt does not expire, it can last indefinitely when stored correctly.


In this brief guide, we answered the question “How many atoms in a grain of salt?”, discussed answers to other related questions like how long does salt last and does salt expire.


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