What is the concentration (in M) of a solution that was prepared by diluting 4.00 mL of a 0.800 M CuCl2 stock solution in a 30.00 mL volumetric flask?

Because you ate playdough

Answer:

5.6⋅10−^19  j

do you need the explaination?

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.