Lewis acids and bases Lewis acids and bases A Lewis acid is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any species that has a filled orbital containing an electron pair which is not involved in bonding but may form a dative bond with a Lewis acid to form a Lewis adduct. For example, NH is a Lewis base, because it can donate its lone pair of electrons. Trimethylborane (MeB) is a Lewis acid as it is capable of accepting a lone
Nasik magic hypercube original definition of nasik.<br> A "nasik" magic cube would have 13 magic lines passing through each of its "m" cells. (This cube also contains 9"m" pandiagonal magic squares of order "m".)<br> A "nasik" magic tesseract would have 40 lines passing through each of its "m" cells.<br> And so on. In 1866 and 1878, Rev. A. H. Frost coined the term "Nasik" for the type of magic square we commonly call "pandiagonal" and often call "perfect". He then demonstrated the concept with an order-7 cube we now class as "pandiagonal", and an order-8 cube we class as "pantriagonal".<br> In another 1878