Interesting question. It might be encoded in DNA. It is different for different organisms like plants and animals It also depends on the tissues and organs. Function, position etc. will decide the geometry.
Heavy ammonia is represented by ND3. What is special about this is, instead of normal protium isotope of hydrogen, 1H1, there are deuterium isotopes, 2H1, also represented by D. The MW is 20 g mol-1. That is why we call it heavy ammonia. Normal ammonia's MW is 17 g mol-1.
We know that Grignard reagent, GR is strongly basic and can abstract a proton from alcohols. This reaction is not possible with NaOH i.e., it cannot abstract proton from alcohols. So GR is stronger base than NaOH
We also know that sodium hydroxide is just enough to abstract a proton from active methyl group of acetaldehyde to carry out aldol reaction.
Now my point is, if we use Grignard reagent, acetaldehyde should undergo aldol reaction instead of Grignard reaction.
Good questions. Diamond is a network solid and melting has no meaning for it. I mean there are no constituent atoms/molecule but only one big molecule of carbons atoms. Since the C-C bonds are very strong, it requires very high energy to break them and if it occurs; that is no longer diamond but gaseous carbon atoms.