Question

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:

• Option 1: Accretion of planetesimals and protoplanets does not involve melting of solid materials in the nebula.
• Option 2: Solid particles form from nebular materials (e.g., dust grains) which is part of the accretion process.
• Option 3: Gravitational pull (not push) acts on nebular materials during accretion.
• Option 4: Trapping of gases and clumping of matter (aggregation) occurs as planetesimals and protoplanets form.
• Option 5: Gas grains grow with addition of atoms and molecules (accretion process).

Answer:

B. Both involve the formation of solid particles from nebular materials, D. Both involve the trapping of gases and the clumping of masses of matter, E. Both involve the growing of gas grains with the addition of atoms and molecules.