The light-year is defined to be the

a. time it takes light to travel from the Sun to the Earth

b. time it takes for light to travel from the nearest star to the Earth

c. distance light travels in one year in space

d. average distance between the Earth and the nearest star

QUESTION 2 In the process of nuclear fusion,

a. two or more nuclei fuse or stick together to form a heavier nucleus whose combined mass is slightly greater than the original nucleus

b. two or more nuclei fuse or stick together to form a heavier nucleus whose combined mass is slightly less than the original nucleus

c. a heavy nucleus breaks apart into a number of smaller nuclei whose combined mass is less than the original nucleus

d. two or more nuclei fuse or stick together to form a heavier nucleus that has exactly the same mass as the original nucleus

QUESTION 3 In our solar system, terrestrial planets are

a. large, made of pure gases with low densities, and found far from the Sun

b. small, made mostly of rock and iron with high densities, and found close to the Sun

c. small, made of pure rock with high densities, and found close to the Sun

d. large, made mostly of gases and liquids with low densities, and found far from the Sun

QUESTION 4 In our solar system, Jovian planets are

a. large, made mostly of gases and liquids with low densities, and found far from the Sun

b. large, made of pure gases with low densities, and found far from the Sun

c. small, made of pure rock with high densities, and found close to the Sun

d. small, made mostly of rock and iron with high densities, and found close to the Sun

QUESTION 5 Between the orbits of the planets Mars and Jupiter we find

a. the asteroid belt

b. the Kuiper belt

c. the Oort cloud

d. Orion's belt

A light-year is a measure of distance used for most space objects, it's the total distance that a beam of light travels (in a straight line) in one Earth year. One light-year is about 6 trillion miles (9 trillion km). Therefore the correct answer is c. the distance light travels in one year in space.

Nuclear fusion is a process where two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles (neutrons or protons). The element formed has more neutrons or more protons than that of the starting material. For example, hydrogen and hydrogen can fuse to form helium. Therefore, the correct answer is a. two or more nuclei fuse or stick together to form a heavier nucleus whose combined mass is slightly greater than the original nucleus

A terrestrial planet is made up of rocks or metals with a hard surface, they have a molten heavy-metal core (mostly iron), few moons and topological features like valleys, volcanoes, and craters. Some examples of this kind of planets in our solar system are Mercury, Venus, Earth and Mars (closer to the sun). Therefore the correct answer is b. small, made mostly of rock and iron with high densities, and found close to the Sun.

Jovian planets are the largest of the outer planets, they are gas giants, composed primarily of hydrogen and helium, they have large systems of moons and ring systems as well. In our solar system, these planets are Jupiter, Saturn, Uranus, and Neptune. Considering this information we can conclude the correct answer is b. large, made of pure gases with low densities, and found far from the Sun.

The asteroid belt is a region of space between the orbits of Mars and Jupiter where most of the asteroids in our Solar System are found orbiting the Sun. Most of the asteroids in the Main Belt are made of rock and stone, but a small portion of them contain iron and nickel metals. The correct answer is a. the asteroid belt

I hope you find this information useful and interesting! Good luck!