Elemental Bomb

You hold a metal shell in your hands and infuse the shell with elemental magic. You can choose acid, cold, fire, lightning, poison, or thunder for the damage type of the bomb. When you create the bomb you can either throw the bomb as a part of the same action or save the bomb for later. If you chose to save it, the energy will hold for one hour before it fizzles out. You can throw the bomb up to 50ft feet away, once the bomb lands the timer starts. The bomb begins to tick and one round after it lands it explodes, dealing 4d8 of the chosen damage to whoever is with a 10ft radius around the object that fails a Dexterity saving throw.

For each level above 1st level, the bomb deals an extra 2d8 of the chosen damage type.