There are 6.50 g of ²⁴Na after 60 hours. How many grams were in the original sample if its half-life is 15 hours? Your answer must include the math used to arrive at the answer.

What energy conversion occurs when a sling shot is used to shoot a rock across the room? (2 points) question 2 options: 1) stored mechanical energy is converted to mechanical energy. 2) stored mechanical energy is converted to radiant energy. 3) gravitational energy is converted to radiant energy. 4) gravitational energy is converted to mechanical energy.