Question

describing the formation of planetesimals and protoplanets
which statements describe processes involved in the accretion of planetesimals and protoplanets? check all that apply:
□ both involve the melting of solid materials in the nebula.
□ both involve the formation of solid particles from nebular materials.
□ both involve the work of the gravitational push on nebular materials.
□ both involve the trapping of gases and the clumping of masses of matter.
□ both involve the growing of gas grains with the addition of atoms and molecules.

Explanation:

• Planetesimals form when solid particles clump from nebular materials, then grow via accretion. Protoplanets form as planetesimals collide and merge, also starting from solid nebular particles.
• Melting is not a required process for either's accretion. Gravity pulls (not pushes) materials. Trapping gases primarily applies to later planetary stages, not the core accretion of planetesimals/protoplanets. Growing gas grains is not the main process for their formation.

Answer:

• Both involve the formation of solid particles from nebular materials.
• Both involve the trapping of gases and the clumping of masses of matter.