Hope this answers your question Mariaduong159
Radiometric Dating. It's used to find the dates of ricks and other objects based on what the known decay rate of radioactive isotopes. Different forms of this method can also estimate the age of natural and man-made materials.
Answer:
10 neutrons
Explanation:
N=Z-A ie. number of neutrons=mass number-atomic number
N=19-9=10
