Covalent bonds are formed when electrons are shared between elements that are nonmetals. The ammonium ion, NH+4 , would have covalent bonds because both nitrogen and hydrogen are nonmetals. ... So, the bond between this particular hydrogen atom and the central nitrogen is a dative covalent bond.
It is called a dactyloscopy
1) This is a definition.
2) Protons are given by the bottom number (since atomic number = number of protons).
3) Neutrons = (mass number)-(atomic number), which are the top and bottom numbers, respectively.
4) Nuclear fusion involves combining two things together, which is only reflected by the last option.
5) This is a fact.
6) This is a fact.
7) This is a fact.
8) This is a fact.
9) The correct option is the explanation.