Acid Ball

A bright streak flashes from your pointing finger to a point you choose within range and then blossoms with a low roar into an explosion of acid. Each creature in a 20-foot-radius sphere centered on that point must make a Dexterity saving throw. A target takes 8d6 Acid damage on a failed save, or half as much damage on a successful one.

A Damage over time Effect Cover the Blast Zone, Dealing 1d4 Acid Damage to Creature that stay in the zone, Last for 1 min

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.