Let $X$ be any countably infinite set, with the cofinite topology.
Then $X$ is connected, and also, $X$ is the countable union of its singleton subsets, which are proper connected sets.
Also, any two distinct singletons sets are separated.
Let $X$ be any countably infinite set, with the cofinite topology.
Then $X$ is connected, and also, $X$ is the countable union of its singleton subsets, which are proper connected sets.
Also, any two distinct singletons sets are separated.