Answer:
density is defined as the amount of mass contained in unit volume of a body .its si unit is kg/m*3
Answer:
"Scientist use radioactive decay to measure the age of a rock or fossil."
Explanation:
"To establish the age of a rock or a fossil, researchers use some type of clock to determine the date it was formed. Geologists commonly use radiometric dating methods, based on the natural radioactive decay of certain elements such as potassium and carbon, as reliable clocks to date ancient events."