Final answer:
Earth is estimated to be between 4.4 and 4.57 billion years old. The geologic time scale is used to describe events in Earth's history.
Step-by-step explanation:
The age of Earth is estimated to be between 4.4 and 4.57 billion years old. This age is based on the oldest rock minerals found on Earth, which are at least 4.404 billion years old.
The geologic time scale is used to describe events in Earth's history, and it divides Earth's history into units based on major changes in geology, climate, and the evolution of life.