well, we can say that √2 and √7 are irrational numbers, they do not provide a value that can be written in a "ration" or fractional.
we can also say that √2 * √7 is √(14), which is also irrational.
However, how about √7 * √7, that's √7² or namely just 7, and that's a rational, so nope, not always.
