Group 1 metals react with water to produce metal hydroxides and hydrogen gas.

Here's the general reaction:

2M(s) + 2H₂O(l) → 2MOH(aq) + H₂(g)

Where:

* M represents a Group 1 metal (like lithium, sodium, potassium, etc.)

* MOH represents the corresponding metal hydroxide

The reaction is highly exothermic (releases heat) and can be quite vigorous, especially with heavier Group 1 metals.