Suppose you go outside and look at three stars. Star A is blue, star B is white, and star C is red. Which star is the hottest, a
nd which star is the coldest? (Figure 4)
a. Star A is the hottest, and star C is the coldest.
b. Star B is the hottest, and star C is the coldest.
c. Star A is the hottest, and star B is the coldest.
Answer: Mid-ocean ridges are geologically important because they occur along the kind of plate boundary where new ocean floor is created as the plates spread apart. Thus the mid-ocean ridge is also known as a "spreading center" or a "divergent plate boundary." The plates spread apart at rates of 1 cm to 20 cm per year.
