Which property of iron is a physical property

a. ability to burn
b. ability to decompose
c. ability to bond
d. ability to conduct heat

08.01 hope this and can i get brainlist? ?

Ijust took the quiz. their is no coefficient needed. : )

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.

Ithink the answer is 10.576