Elemental Strikes

You touch a melee weapon in your possession and imbue it with elemental energy, choosing from acid, cold, fire, lightning, poison, or thunder. Until the start of your turn, attacks with that weapon deal 1d8 damage of the elemental damage type chosen.

If you touch a weapon with the Light property, you can immediately make a single weapon attack with it as part of the same action as casting the spell.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the spell lasts for an additional round for each level above 1st.

Source: Kibble's Casting Compendium