The Environmental Protection Agency has ben concerned about the levels of radon gas in homes. If a sample of gas taken from a basement contains 4.38 g of radon 222, how much radon will remain in the sample after 4 half-lives? 0.28 g

2.19 g

1.10 g

4.38 g

Which of the following statements are true of solids? a.the particles do not vibrate. b.the particles are in a fixed location. c.they have strong intermolecular forces between the atoms or molecules. d.the particles have less kinetic energy than those of liquids or gases.

Un jugador de beisbol batea un foul recto en el aire.la pelota deja el bate con una rapidez de 120 km/h. en ausencia de resistencia del aire. ? cual sera la rapidez de la pelota cuando la atrape el catcher

Using a pedometer, you walk 3000 steps in 20 minutes, so your speed is 150 steps/min. each of your steps is 0.7 m long. what is your speed? 150 steps/min=/s=/h