Why is the average atomic mass used when calculating grams of a substance? O A. The number of isotopes in the sample is constantly changing. B. The average atomic mass is known to more significant figures. O C. The elements in the substance are mixtures of their isotopes. O D. The exact weights of the isotopes are not known.​

60.0 - there are 3 significant numbers

1.75 is the weight of one medium egg

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.

Hcn is your answer my guy : )