Because that's where they come from. Coal, oil, and natural gas are the products
of dead dinosaurs rotting in the ground under great pressure for millions of years.
1 mL = 1 cm³
D = m / V
0.7857 = m / 17.16
m = 0.7857 x 17.16
m = 13.482 g
Yes, it's changing the appearance of the metal caused by rain, salt, or acid
