Acertain liquid has a density of 2.67 g/ cm3. what is the mass of 30.5 ml of this liquid? (

Hey there!

density = 2.67 g/cm³

volume = 30.5 mL

Therefore:

Mass = density * volume

Mass = 2.67 * 30.5

Mass = 81.435 g 

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.