_____ Are Subdivisions of Eras

Q4: The Earth's largest mass extinction coincides with

Q5: The relative-dating principle of _ states that

Q6: Our ability to assign an age to

Q7: In radioactive decay a(n) _ emission is

Q8: Isotopes of the same element have different

Q10: A(n) _ fossil is a fossil from

Q11: _ denotes the vast amount of time

Q12: The _ Era is the Age of

Q13: So far, the oldest mineral found on

Q14: _ is the spontaneous nuclear change of