Question

increase, forming a protostar. as the protostar gathers more matter via gravity, its internal pressure and temperature can become extreme enough for hydrogen atoms in its core to fuse together to form helium atoms. thus, a new star is born. after a new star forms, it is still surrounded by a large cloud of gas and dust. this cloud rotates around the new star and flattens into a protoplanetary disk. over time, the new star absorbs most of the disks nearby matter, while the more distant matter condenses into clumps with greater masses and densities than those of surrounding objects. gravity can pull these clumps of dust, ice, and rocks together to form comets, asteroids, or the building blocks of planets and moons. these objects gravitational influences increase as they gain more matter and become more massive. eventually, planets and moons can form, and the protoplanetary disk can become a new planetary system. this is the process by which the solar system formed. match the terms to their descriptions. protostar star protoplanetary disk gravitational collapse nebula a hot, dense celestial object formed when a cloud of gas and dust collapses in on itself due to gravity a flattened, rotating cloud of gas and dust surrounding a newly formed star, from which comets, asteroids, and planets can form the inward contraction of a cloud of gas and dust as it gets more massive and its gravity increases an extremely hot, dense celestial object with high enough core temperature and pressure for hydrogen atoms to fuse into helium atoms a large, cloud - like structure in space—mostly made of gas and dust—from which stars can form

Explanation:

Each term is matched to its description by cross-referencing the definitions provided in the text above the matching exercise.

1. The first description refers to the early stage of a star before hydrogen fusion starts, which is a protostar.
2. The second description defines the flattened disk around a new star, which is a protoplanetary disk.
3. The third description is the inward squeeze of a gas/dust cloud, which is gravitational collapse.
4. The fourth description is a star where hydrogen fusion occurs in the core.
5. The fifth description is the large cloud of gas/dust that forms stars, which is a nebula.

Answer:

1. protostar - A hot, dense celestial object formed when a cloud of gas and dust collapses in on itself due to gravity
2. protoplanetary disk - A flattened, rotating cloud of gas and dust surrounding a newly formed star, from which comets, asteroids, and planets can form
3. gravitational collapse - The inward contraction of a cloud of gas and dust as it gets more massive and its gravity increases
4. star - An extremely hot, dense celestial object with high enough core temperature and pressure for hydrogen atoms to fuse into helium atoms
5. nebula - A large, cloud-like structure in space—mostly made of gas and dust—from which stars can form