\begin{tabular}{l} Is \( \sqrt{7} \) a rational number? \\ yes no \\ \hline\end{tabular}

To determine whether \( \sqrt{7} \) is a rational number, we first need to know that a rational number can be expressed as a fraction of two integers, where the denominator is not zero. Since \( \sqrt{7} \) cannot be expressed this way, it is classified as an irrational number. It has a non-repeating, non-terminating decimal expansion, approximately equal to 2.6457513110645906. Interestingly, the concept of irrational numbers was first introduced by the ancient Greeks when they encountered the square root of 2, which was notably controversial at the time. The discovery of irrational numbers expanded the realm of mathematics and led to further developments in algebra, geometry, and number theory, reshaping our understanding of numbers forever!