"Mole Day is an unofficial holiday celebrated among chemists in North America on October 23, between 6:02 AM and 6:02 PM, making the date 6:02 10/23 in the American style of writing dates. The time and date are derived from the Avogadro constant, which is approximately 6.022×1023, defining the number of particles (atoms or molecules) in a mole, one of the seven base SI units."

A mnemonic (pronounced [nəˈmɒnɪk] in RP, [nɪ'mɑnɪk] in GA) is a memory aid that generally serves an educational purpose. They are mostly verbal, e.g a word, each of whose letters help the user to remember the first letters of items in a list. However, there are also other types of mnemonics, such as visual mnemonics. Mnemonics rely on associations between something that is easy to remember, and something that is harder to remember. Sometimes mnemonics are chosen to directly relate to the target information, and othertimes they are arbitrary.