In a semiconductor fabrication process, a silicon wafer is doped using an ion implanter that produces a beam of doubly-charged phosphorus ions (P2+P^{2+}P2+). The beam current is measured to be 0.80 mA. How many phosphorus ions strike the wafer during an exposure time of 4.0 minutes4.0\text{ minutes}4.0 minutes?
1.0×10161.0 \times 10^{16}1.0×1016
1.2×10181.2 \times 10^{18}1.2×1018
6.0×10176.0 \times 10^{17}6.0×1017
6.0×10206.0 \times 10^{20}6.0×1020
