TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: Monatomic ions form when a single atom gains or loses electrons.

SOLUTION: What form when a single atom gains or loses electrons?

PROBLEM: In their processes of gene expression, archael cells seukaryotic similarties to both bacterial cells and which other type of cell.

SOLUTION: In their processes of gene expression, archael cells show similarties to both bacterial cells and which other type of cell?

PROBLEM: Steam is harmless water vapor, for a powerplant.

SOLUTION:
What is harmless water vapor, for a powerplant?