Question

1. the earth achieved its internal heat by * 8 points

no yes
bacteria
breaking down of radioactive elements
gravity compression/compaction
friction: meteorites and asteroid striking the earth
friction: formation of earth as denser material is sinking
meteorites and comets
volcanic eruptions
sun

Explanation:

• Bacteria: No role in Earth's internal heat formation.
• Breaking down of Radioactive elements: Radioactive decay is a key ongoing source of Earth's internal heat.
• Gravity Compression/Compaction: Gravitational compression during Earth's formation generated heat.
• Friction: Meteorites and Asteroid striking the Earth: Impacts during accretion generated frictional heat.
• Friction: Formation of Earth as denser material is sinking: Differentiation (dense material sinking) created frictional heat.
• Meteorites and Comets: Impacts brought some heat, but this is covered by the impact friction point; the objects themselves are not a heat source.
• Volcanic Eruptions: These are a result of internal heat, not a source.
• Sun: The Sun heats Earth's surface, not its interior.

Answer:

• Bacteria: No
• Breaking down of Radioactive elements: Yes
• Gravity Compression/Compaction: Yes
• Friction: Meteorites and Asteroid striking the Earth: Yes
• Friction: Formation of Earth as denser material is sinking: Yes
• Meteorites and Comets: No
• Volcanic Eruptions: No
• Sun: No