A rock has a mass of 40 grams. When analyzed the rock is found to contain 10 grams of radioactive material 30 grams of a stable product. How many half-lives old is the rock?

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

When curium-242 is bombarded with an alpha particle, two products are formed, one of which is a nudge on. what is the other product

22. a flask containing 450 ml of 0.50 m h2so4 was accidentally knocked to the floor. how many grams of nahco, do you need to put on the spill to neutralize the acid according to the following equation: h2so4(aq)+2 nahcos(aq) na,so(aq) +2 h20()+2 co2(g) d) 38 g a) 2.3 g b) 9.5 g c) 19 g