Yes, 1/7 is a rational number.
A rational number is defined as any number that can be expressed as the quotient or fraction of two integers, where the numerator is an integer and the denominator is a non-zero integer. In this case, 1 is the numerator and 7 is the denominator. Since both 1 and 7 are integers and 7 is not zero, 1/7 meets the criteria for being a rational number.
Furthermore, rational numbers can be either positive or negative, and they can also be expressed in decimal form. The decimal representation of 1/7 is approximately 0.142857, which is a repeating decimal. Despite being a repeating decimal, it is still rational because it can be written as a fraction.