constant [constants](that which is permanent or invariable) noun [UK: ˈkɒn.stənt] [US: ˈkɑːn.stənt]
константа Авогадро proper noun {f}
Avogadro's number(number of atoms present in 0.012 kilograms of isotopically pure carbon-12) proper noun [UK: ˌæ.vəʊ.ˈɡɑː.drəʊz ˈnʌm.bə(r)] [US: ˌævo.ʊ.ˈɡɑːdroʊz ˈnʌm.br̩]