PHB
Elemental Weapon
3-level Transmutation
Casting Time: 1 action
Range/Area: touch
Components: V, S
Duration: Concentration, 1 hour
A nonmagical weapon you touch becomes a magic weapon. Choose one of the following damage types: acid, cold, tire, lightning, or thunder. For the duration, the weapon has a +1 bonus to attack rolls and deals an extra 1d4 damage of the chosen type when it hits.
At higher levels: When you cast this spell using a spell slot of 5th or 6th level. the bonus to attack rolls increases to +2 and the extra damage increases to
2d4 . When you use a spell slot of 7th level or higher, the bonus increases to +3 and the extra damage increases to
3d4 .