Corvin's Chromatic Arrow

When you cast the spell, you choose acid, cold, fire, lightning, poison or thunder. The next time you make a ranged weapon attack during the spell’s duration, the weapon’s ammunition, or the weapon itself if it’s a thrown weapon, transforms into the chosen type. The weapon’s damage becomes the chosen type, and deals an additional 1d8 damage.

The ammunition or weapon then returns to its normal form.

 At Higher Levels: When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d8 for each slot level above 1st.