Final answer:
The Earth is estimated to be about 4.5 billion years old. The first early, relatively stable land mass formed at the end of the Hadean eon, about 4 to 4.6 billion years ago.
Step-by-step explanation:
The Earth is estimated to have formed about 4.5 billion years ago. At first, the Earth was molten and lacked an atmosphere and oceans. Gradually, the atmosphere formed, followed by the oceans. The first early, relatively stable land mass formed after the solidification of the molten surface at the end of the Hadean eon, which was about 4 to 4.6 billion years ago.