An example of a teaching analogy:
"Coordinate covalent or dative bonding is often described in a simple fashion by saying that it involves one atom donating or giving a pair of electrons to another, so that this bonding partner can have a full outer shell. When electrons are counted up in an electronic dot diagram, this coordinate covalent pair is counted with each of the atoms. It is similar to borrowing a pair of books from the public library: the books are given to you and you treat them essentially as if they belonged to you; yet at the same time the books are counted as being part of the library collection."
Source: Murray Hart, retired science teacher, previously posted at scienceanalogies.com
Read examples of scientific analogies
Read about the octet framework for understanding chemical bonding