The empty spaces in a material are called pores. Porosity is the amount of empty space within a material. Permeability describes how well the pores in a material are connected. Which of these materials will make the most effective aquifer?

Woah that’s a lot to read xd i’ll try though. i’ll get back t you if. i know the andwer

U whay do you need with?

The correct answer is b) false

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.