Can u pls help me with this question

Asample contains 16.75 g of the radioisotope u-236 and 50.25 g of its daughter isotope, th-232. how long did it take for decay to take place if one half-life of u-236 is 23 million years? 46 million years 69 million years 92 million years 115 million years

If 22.5 liters of oxygen reacted with excess of hydrogen, how many liters of water vapor could be produced?

Why does a plastic bottle that is sealed at a high altitude change it’s shape when taken to lower altitude