Final answer:
The electron's speed of 1368 miles per second is equivalent to 4,924,800 miles per hour when converted, making the answer (a) 4,924,800 miles per hour.
Step-by-step explanation:
The typical speed of an electron circling the nucleus of an atom is given as 1368 miles per second. To find out how fast this is in miles per hour, we can perform a unit conversion by multiplying the given speed in miles per second by the number of seconds in an hour (3600 seconds).
Here's the calculation: 1368 miles/second × 3600 seconds/hour = 4,924,800 miles/hour.
So, the correct answer is 4,924,800 miles per hour, which means the correct option is (a) 4,924,800 miles per hour.