What is the frequency of a photon that has the energy of 8.46x10^-19 j?

The frequency of the photon is 1.28 PHz.

E = hf

f = E/h = 8.46 × 10⁻¹⁹ J/6.626 × 10⁻³⁴ J·s = 1.28 × 10¹⁵ s⁻¹ = 1.28 PHz

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.

it is b that is the answer.