Which process represents one chemical change and one physical change?

What are the resulting coefficients when you balance the chemical equation for the combustion of ethane, c2h6? in this reaction, ethane is burned in the presence of oxygen (o2) to form carbon dioxide (co2) and water (h2o). (g)+(g)→(g)+(g)

Which radioisotope is used to date fossils? a. oxygen-16 b. carbon-14 c. uranium-238 d. carbon-12

If an atom has 12 protons and 13 neutrons