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.
What is the term for a word which is another word spelled backwards? There's no generally accepted term. The simplest way of referring to such words (e.g. lap/pal, dog/god) is probably semi-palindrome or half-palindrome. Some other suggestions have been made, including heteropalindrome, reversgram (or reversible anagram), and semordnilap (i.e. palindromes written backwards). See other Vocabulary Questions.