Answer : first opinion and also last
Expiation : Note that these last two reactions, and 2H + 2H → 4He + γ, .Nuclear fusion is a reaction in which two nuclei are combined to form a larger nucleus. Nuclear fusion is a reaction in which two nuclei are combined, or fused, to form a larger nucleus. We know that all nuclei have less mass than the sum of the masses of the protons and neutrons that form them. The missing mass times c2 equals the binding energy of the nucleus—the greater the binding energy, the greater the missing mass.
The answer is ligand: a molecule or ion that can bond to a (central) metal ion (to form a complex);
NH3: Lewis base and Cu2+: Lewis acid (need both for mark);
<span>each NH3/ligand donates an electron pair (to Cu2+); forming coordinate covalent/dative covalent bond; i hope this help you.</span>
Crystal system
Hardness
Tenacity or Toughness