start with of 640g isotope x with a decay product of isotope y for this problem which has a half life of 15 min

Im is in a crowd of people at the mall looking for his girlfriend tammy, who was supposed to meet him for dinner. jim realizes tammy is across the room as he catches a whiff of her overpowering perfume, 'paris #6'. which process explains why jim is able to smell the perfume?

What are the characteristics of living things

Apaleontologist finds a plant fossil that shows that the plant had seeds. what can the paleontologist conclude?