Part A Separate the pennies you have into two groups: one group with pennies dated before 1982 and the other with pennies dated before 1982. Compare the two groups record any similarities or differences in size or appearance that you notice between the groups. (Activity: identifying a substance by its properties)

The pennies are all the same shape and diameter, they are circular and under an inch in diameter. The pennies dated before 1982 are "95 percent copper and 5 percent zinc" and are a darker and duller color than the pennies dated after 1982.

The pennies that are dated after 1982 are "97.5 percent zinc and 2.5 percent copper" and are brighter and shinier than the pennies dated before 1982.

Explanation:

Correct via Edmentum

(make sure to put the answer in your own words, do not copy and paste)

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.