The difference between an insulator and a semiconductor is (a) a wider energy gap between the valence band and the conduction band (b) the number of free electrons (c) the atomic structure answers (a), (b), and (c)

hi my dude or dudette

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.

the answer is d. 74.02