Water has a density of 1000 kg/m3 by standard definition at its temperature of maximum density 3.98 Â°C and at 0% salinity. Scientists and engineers use water as a baseline for comparing the relative density of various materials. Water with a density of 1000 kg/m3 at 3.98 Â°C has a mass of 1000kg and a volume of 1 m3.
Spelt is a word. It is the past participle of spell. It is also a type of wheat, and therefore also a noun. It depends upon whether you are using British English (and Spelt is correct) or you are using American English.
Old English spelt, perhaps an early borrowing from Late Latin spelta spelt (c.400, noted as a foreign word), which is perhaps ultimately from PIE root *spel- to split, to break off (probably in reference to the splitting of its husks in threshing), which is related to the root of flint.