Is this investigation a controlled experiment or an observational study? Explain your answer.

B) movement of materials into and out of the cell

Radon-222 or rn-222 has a half-life of 3.82 days. to determine the fraction of an original sample of rn-222 that remains unchanged after 7.646 days, we calculate the amount of rn-222 remaining after 7.646 days and divide it with the original amount. using 1 gram as a basis and using half-life calculation methods, we can determine that  0.249 or 0.25  grams of rn-222 will remain, and thus the fraction remaining is 0.25 or 1/4.

The statement that most describes one way global winds affect weather and climate is a. polar easterlies move cool air to mid-latitudes. this is correct because the closer an area is to the equator the hotter it is, therefore if the polar winds are being moved towards the mid-latitudes it cools them down. 

The chlorine is the chemical property