Once per turn when you hit with a Bomb or use the Bomb's Explode property, you can expend 1 ValdaSpire24 to add 1d10 to the Bomb's damage roll. When you reach certain Alchemist levels, you can expend more ValdaSpire24, up to the number shown in the Prime Bomb column of the Alchemist Features table, adding 1d10 damage for each ValdaSpire24 expended.
If you use the Bomb's Explode property, you can also increase the radius of the explosion up to 5 feet for each ValdaSpire24 expended in this way. For example, if you expend 2 ValdaSpire24 at Alchemist level 5, the Bomb deals an extra 2d10 damage and you can choose for the Sphere to be a 5, 10 or 15-foot-radius.