Water doesn't fall slowly or gently. It may flow down a slope differently than if it were falling, but when it falls, it does so at the same rate of acceleration as any other falling solid or liquid:32 ft/sec/sec.
it falls to the bottem of the water
it gets cooler
slowly evaporates.
It melts slowly.
when water falls on a cemented ground the cemented ground can't absorve water much and the water flows away.
water magically falls from the sky
the water slowly erodid away the sediment till the river was foremed and it was the in direction of a cliff
It melts slowly.
Nothing noteworthy happens if mentos are put in tap water; they simply dissolve slowly.
It will sink. And it will slowly oxidize from the dissolved oxygen in the water.
That is called evaporation when it happens slowly; if it happens more rapidly it is called vaporization.
Carbon mixes with the rain water and when it falls, it wears out rocks. So it happens when the rain water mixes with the carbon from the air.