Putting an opened can of soda in the refrigerator is perfectly safe and is a common practice to keep the drink cool and refreshing for later consumption. In fact, refrigerating an opened can of soda can help preserve its taste and carbonation for a longer time compared to leaving it at room temperature.
When a can of soda is opened, it's exposed to the air, and some of the carbonation will start to escape gradually. The carbon dioxide gas in the soda is what gives it its characteristic fizz, and refrigeration can help slow down the rate at which the carbonation dissipates. Additionally, refrigeration can also help maintain the flavor of the soda, especially if it contains natural fruit flavors or other delicate ingredients that might be affected by heat or prolonged exposure to air.
So, to enjoy your soda at its best, it's a good idea to put the opened can in the refrigerator if you don't plan to finish it all at once. Just make sure to cover the can with a lid or wrap it with plastic wrap to prevent any odors from the fridge from seeping into the drink and affecting its taste.