The point of the initial energy release of an earthquake is called the
a. shadow zone.
b. subduction zone.
c. focus.
d. epicenter.
Question 2
In addition to those of Groups 1A and 2A, three common elements that form only one ion each are
a. Sc, Ti, and Hg.
b. Pb, Sn, and Cu.
c. Al, Zn, and Ag.
d. Ga, Ni, and Fe.