Question

Which allowed scientists to determine that Earth was at least 4.3 billion years old?(1 point)
Responses

chemical reactivity of zircon ions
chemical reactivity of zircon ions

magnetic field surrounding zircon
magnetic field surrounding zircon

the electrical conductivity of uranium ions
the electrical conductivity of uranium ions

the radioactive decay of uranium to lead

Answer 1

The correct response is:

**the radioactive decay of uranium to lead**