The half -life if Po - 218 is three minutes . How much of a 2.0 gram sample remains after 15 minutes? Suppose you wanted to buy some of this e , and it required half an hour for it to reach you. How much should you order if you need to use 0.10 gram of this material ?

While goofing off at the ice skating rink, a student takes off her shoes and places each of them on the ice. her friend, a hockey player, then shoots a hockey puck at each shoe. the first puck immediately comes to rest after it collides with the left shoe. the second puck rebounds after it collides with the right shoe. if each hockey puck has the same incoming speed, which shoe has greater speed after the collision? the right shoe. both shoes have the same speed. the left shoe.

What are the three ways that an object can accelerate

The first-order reaction a→2b+c has rate constant 0.538 s−1. if the initial concentration of a is 0.867 mol l−1, what is the half-life of the reaction in seconds? remember to use correct significant figures in your answer (round your answer to the nearest hundredth). do not include units in your response.