Answer:
20 neutrons
Explanation:
neutrons = mass number - atomic number
mass number = 39, atomic number = 19
neutrons = 39 - 19 = 20
Answer:
B- how much time it took a fossil to form
Explanation:
To determine the ages in years of Earth materials and the timing of geologic events such as exhumation and subduction, geologists utilize the process of radiometric decay.