Final answer:
The square root of 10, represented as √10, is an irrational number because it cannot be expressed as a fraction or a terminating decimal.
Step-by-step explanation:
An irrational number is a number that cannot be expressed as a fraction or a terminating or repeating decimal. Out of the options given, √10 represents an irrational number because the square root of 10 cannot be expressed as a fraction or a terminating decimal.