Earth Science 1 : 1 Four

Which statement is true?

*Inner and outer planet composition supports the nebular theory because heavier elements condense close to the Sun, and lighter elements condense at cooler temperatures.* The big bang is a theory about the origin of the solar system. Nuclear fusion occurs at cooler temperatures, away from the Sun. The inner planets are gas giants, and the outer planets are rocky.

The *BLANK* theory suggests that protoplanets began to form around the protosun from many collisions and combinations of gas and matter, called *BLANK*

1. Nebular 2. Accretion

Step 1. Step 2. Step 3. Step 4. Step 5. Step 6.

1. Nebular cloud of gas and dust. 2. Cloud collapses under the force of its own gravitational attraction; usually triggered by a supernova. 3. Condensed material begins to combine and form a core center. As it warms, a protostar is formed. 4. Other gas and matter of the nebular cloud begin to rotate around the protostar, forming a flattened, disk. 5. Stellar core heats as it grows; nuclear fusion begins and a star is born. 6. Nuclear energy runs out; death;

1. Accretion 2. Condensation Theory 3. Interstellar 4. Nebula 5. Nebular Theory 6. Nuclear 7. Nuclei 8. Protoplanet 9. Protostar 10. Solar Nebula 11. Stellar Evolution 12. Supernova

1. Process of steady growth of an object by a steady accumulation of material. 2. Theory about the origin of the solar system that agrees with the nebular theory, but stresses the importance of interstellar dust in planet formation. 3. Among or between stars. 4. Enormous cloud of gas and dust in space. 5. Theory about the origin of the solar system that suggests our Sun and planets formed from a nebula, a cloud of dust and gas. 6. A nuclear reaction where nuclei combine and release intense energy. 7. The centers of atoms which contain most of their mass. 8. A planet in its first stage of development. 9. A star in its first stage of development. 10. Cloud of gas and dust from which our solar system formed. 11. The life cycle of a star. 12. An explosion of a star that emits large amounts of matter and energy.

Which of the following is not one of the observed characteristics of our solar system?

All moons orbit planets in a counterclockwise direction.

Observations of the solar system support the nebular theory because *BLANK*.

All the planets orbit the sun in the same direction along a circular, flattened disk.

The *BLANK* theory suggests that the interstellar dust within a nebular cloud is the most important component of planet formation.

Condensation

A star is held together by:

Gravity & Nuclear Fusion

Heavy elements, such as iron and silicon, have a *BLANK* condensation temperature as compared to light elements, such as hydrogen and helium.

Higher

The outer planets are mostly formed of the lighter elements, hydrogen and helium, because these elements condense at a *BLANK* temperature, further from the Sun.

Lower

Current observations of a new star forming support the nebular theory because they show a disk-shaped plane surrounding the star, which may eventually form *BLANK*.

Protoplanets

When a star's nuclear energy runs out, it dies. A star can die in many ways. A *BLANK* is one way a star might die, and it can trigger the beginning of a new star's life cycle.

SuperNova

A protostar forms once the nebular cloud condenses and the core begins *BLANK*

To Heat