About National Mole Day

How long until National Mole Day?

National Mole Day .

Dates of National Mole Day

2025 USA Thursday, October 23rdNational Mole Day

2024 USA Wednesday, October 23rdNational Mole Day

2023 USA Monday, October 23rdNational Mole Day

2022 USA Sunday, October 23rdNational Mole Day

2021 USA Saturday, October 23rdNational Mole Day

Summary

October 23, denoted 10/23 in the US, is recognized by some as Mole Day. It is an informal holiday in honor of the unit among chemists.

National Mole Day recognizes a special number in chemistry. Chemists and chemistry students mark the occasion each year on October 23.

The mole is the unit of amount in chemistry. It provides a bridge between the atom and the macroscopic amounts of material that we work with in the laboratory. It allows the chemist to weigh out amounts of two substances, say iron and sulfur, such that equal numbers of atoms of iron and sulfur are obtained.

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