The ratio of radii of two nuclei of mass numbers 1 and 27 is

The correct answer is (c) 1 : 3.

The radius of a nucleus is approximately proportional to the cube root of its mass number. This means that the radius of

a nucleus with a mass number of 27 is about 3 times the radius of a nucleus with a mass number of 1.

Option (a) is incorrect because the radius of a nucleus is not directly proportional to its mass number. Option (b) is incorrect because the radius of a nucleus is not inversely proportional to

its mass number. Option (d) is incorrect because the radius of a nucleus is not equal to 5 times the radius of a nucleus with a mass number of 1.