Answer
$\bf{diverges \ series }$
Work Step by Step
The sum of a convergent infinite geometric series is given by the formula:
$S_{\infty}=\dfrac{a_1}{1-r}$ and a geometric series converges if $|r| \lt 1$ and an infinite geometric series diverges if $|r| \gt 1$.
Therefore, our missing expression in the given statement is:
$\bf{diverges \ series }$
