1. Problem statement: Evaluate the expression $\sqrt{7}-\sqrt{2}\{2\}$. 2. Interpretation: We interpret $\{2\}$ as the fractional part of 2, defined by $\{x\}=x-\lfloor x\rfloor$. 3. Compute the fractional part: Since 2 is an integer, $\{2\}=0$. 4. Substitute into the expression: The expression becomes $\sqrt{7}-\sqrt{2}\cdot 0$. 5. Simplify: $\sqrt{2}\cdot 0=0$. 6. Final evaluation: $\sqrt{7}-0=\sqrt{7}$. 7. Answer: Therefore the value is $\sqrt{7}$.