Can u help me on these science questions cause i dont get them?

2. how does the formation of an ionic bond differ from the formation of a covalent 3.what is meant by the term valence electron how many valence electrons dooes sulfar have 4. how do ionic compounds differ from molecular compounds when added to water 5.how is a polymer like a chain link fence?what would be represented by each linkin the chain please number off answers thanks