How many nuclei of u remain in a rock if the activity registers 280 decays per second(note that the half life of uranium-238 is 4.468x10 years)

Difference between series and parallel circuits

What is the freezing point of radiator fluid that is 50% antifreeze by mass? kf for water is 1.86 ∘c/m.

On your wedding day your lover gives you a gold ring of mass 3.67 g. 48 years later its mass is 3.44 g. on the average how many atoms were abrated from the ring during each second of your marriage? the atomic mass of gold is 197 u. don't enter units