Final answer:
Sunspots occur in cycles, with the maximum number occurring approximately every 11 years, although this can vary between 9 and 14 years.
Step-by-step explanation:
Sunspots occur in cycles with the maximum number of sunspots occurring about every 11 years. Heinrich Schwabe, a German pharmacist and amateur astronomer, discovered the sunspot cycle through persistent observations. These sunspots are cooler, dark regions on the Sun's surface and can indicate the rate at which the Sun rotates.
The cycle can vary, with maximums ranging from 9 to 14 years, but the average is approximately 11 years. During these peak periods, more than 100 sunspots can often be observed simultaneously, despite occupying less than one-half of one percent of the Sun's surface.