The sunspot diameter is 30,000 km. Can it be seen from Earth with the naked eye? The resolution of the eye is 1 ‘.

Let us introduce the designations: D is the diameter of the Sun, d is the diameter of a sunspot, pc = 30 ‘is the apparent angular diameter of the Sun, p (n) is the apparent angular diameter of a sunspot.
Decision:
D / d = p (c) / p (n); p (n) = d * p (c) / D = 30,000 * 30 / 1.4 * 10 ^ 6 = 0.642.
Since the angular dimensions of the spot are less than 1 ‘, we will not be able to see it.