Plutonium (238Pu) was carried in the Voyager space probes to Jupiter as a power source. 238Pu has also been used as a heat source to power heart pacemaker batteries. In a pacemaker this power system is able to have a life up to 20 years. Compute the activity in units of curies (Ci) for the 0.25 g of pure 238Pu used in the pacemaker battery.