## Chemistry: The Molecular Science (5th Edition)

$NH_3$ is a weak base.
Analyzing the table 14.2 (Page 624), we can see the $K_b$ value for $NH_3$, which is $1.8 \times 10^{-5}$. Compounds with $K_b < 1$ are considered weak bases. - $NH_3$ is capable of acting as an acid too, but, this is very unlikely to happen, because its $K_a$ is a very small number, so, we don't need to consider this.