To multiply the expressions \( \sqrt{7} \) and \( -\sqrt{2} \), you treat them as follows:
\[ \sqrt{7} \cdot (-\sqrt{2}) = -\sqrt{7} \cdot \sqrt{2} \]
By the property of square roots, \( \sqrt{a} \cdot \sqrt{b} = \sqrt{a \cdot b} \), we can combine the radicals:
\[ -\sqrt{7 \cdot 2} = -\sqrt{14} \]
Thus, the product of \( \sqrt{7} \) and \( -\sqrt{2} \) is:
\[ -\sqrt{14} \]