Which event would most likely occur if Earth did not retain the heat from its formation?

• A. Earth's interior would cool rapidly, leading to a lack of geological activity such as volcanism and plate tectonics.
• B. Earth's atmosphere would become significantly thicker due to increased volcanic outgassing.
• C. Earth would develop a stronger magnetic field due to increased core convection.
• D. Earth's surface temperature would rise dramatically, making it uninhabitable for most life forms.

Answer: (A)

Verified step by step guidance

1. Understand the role of Earth's internal heat, which primarily comes from its formation and radioactive decay, in driving geological processes such as volcanism and plate tectonics.
2. Recognize that if Earth did not retain this heat, the interior would lose energy quickly, causing the mantle and core to cool down.
3. Recall that geological activity like volcanism and plate tectonics depends on the movement of molten rock and convection currents within Earth's mantle, which require internal heat.
4. Conclude that without sufficient internal heat, these convection currents would slow or stop, leading to a lack of geological activity.
5. Note that other options, such as a thicker atmosphere or stronger magnetic field, are linked to geological activity and internal heat, so they would not increase if the Earth cooled rapidly.