Only the square root of 1 is a rational number.
A rational number is any number that can be expressed as the quotient or fraction p/q of two integers, where p is the numerator and q is the denominator (and q is not zero).
Let's examine the given numbers:
Square root of 1: √1 = 1. This is a rational number because it can be expressed as 1/1.
Square root of 2: √2 is an irrational number. It cannot be expressed as a fraction of two integers, and its decimal representation goes on forever without repeating.
Square root of 3: √3 is also an irrational number.
Square root of 5: √5 is another irrational number.
Therefore, only the square root of 1 is a rational number.