Diffusion is the movement of molecules from
a. an area of low concentration to an area of high concentration.
b. an area of high concentration to an area of low concentration.
c. an area of equilibrium to an area of high concentration.
d. all of the above

the atomic mass is the bottom number on the element.

-steel jelly

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.