1.
A solar system is
Correct Answer
C. A star and all the objects that travel around it
Explanation
The correct answer is "a star and all the objects that travel around it." A solar system refers to a star, typically the Sun, and all the celestial bodies that orbit around it. This includes planets, moons, comets, and asteroids. The Sun is at the center of the solar system, and the planets and other objects revolve around it due to its gravitational pull. Therefore, the solar system consists of not only the star but also all the objects that are under its gravitational influence.
2.
Scale models help us to understand the Solar System because they
Correct Answer
B. Show relative size and distance of the planets
Explanation
Scale models help us to understand the Solar System by showing the relative size and distance of the planets. By creating models that accurately represent the size and distance of each planet in relation to one another, we can gain a better understanding of the vastness and complexity of our solar system. This allows us to visualize and comprehend the immense size differences between the planets and their distances from the Sun. Scale models provide a tangible representation that aids in our comprehension and appreciation of the Solar System's structure and dynamics.
3.
Jupiter, Saturn, Uranus, and Neptune are known as the
Correct Answer
B. Gas giants
Explanation
Jupiter, Saturn, Uranus, and Neptune are known as gas giants because they are primarily composed of hydrogen and helium gases. These planets have thick atmospheres and lack a solid surface like rocky planets. Gas giants are much larger in size compared to rocky planets and have a lower density. They also have a system of rings and numerous moons orbiting around them.
4.
The inner planets are mostly
Correct Answer
C. Hard and rocky, with craters and few moons
Explanation
The correct answer is "hard and rocky, with craters and few moons." This answer accurately describes the characteristics of the inner planets in our solar system. The inner planets, which include Mercury, Venus, Earth, and Mars, are composed of solid rock and metal. They have a rocky surface with impact craters caused by meteorite collisions. Additionally, compared to the outer gas giants, the inner planets have relatively few moons.
5.
Earth has day and night because
Correct Answer
D. It rotates on its axis
Explanation
The correct answer is that Earth has day and night because it rotates on its axis. As the Earth spins on its axis, different parts of the planet are exposed to the Sun's light, creating the cycle of day and night. This rotation takes approximately 24 hours, resulting in a full day and night cycle. The other options provided, such as revolving around the Sun or having an elliptical orbit, do not directly cause day and night but rather affect the length of daylight throughout the year (seasons). The tilt of Earth's axis does contribute to the changing seasons but is not the primary reason for day and night.
6.
We see the Moon's phases because
Correct Answer
A. We see different amounts of the Moon's lighted surface
Explanation
The phases of the Moon are caused by the different amounts of the Moon's lighted surface that we can see from Earth. As the Moon orbits around the Earth, the angle between the Sun, Earth, and Moon changes, causing different portions of the Moon to be illuminated by sunlight. This changing illumination creates the different phases of the Moon that we observe, such as the new moon, first quarter, full moon, and last quarter.
7.
A year on another planet may be longer than a year on Earth because
Correct Answer
D. The planet has a bigger orbit than Earth
Explanation
The correct answer is that the planet has a bigger orbit than Earth. This is because the length of a year is determined by the time it takes for a planet to complete one full orbit around its star. If a planet has a larger orbit, it will take a longer time to complete one orbit, resulting in a longer year compared to Earth. The other options, such as the planet being bigger or closer to the Sun, do not directly affect the length of a year.
8.
Earth has seasons because
Correct Answer
B. It has a tilted axis and it revolves around the Sun
Explanation
The correct answer is that Earth has a tilted axis and it revolves around the Sun. This is because the Earth's axis is tilted at an angle of about 23.5 degrees relative to its orbit around the Sun. This tilt causes different parts of the Earth to receive varying amounts of sunlight throughout the year, leading to the changing of seasons. As the Earth revolves around the Sun, different hemispheres are tilted towards or away from the Sun, resulting in the different seasons experienced in different parts of the world.
9.
What is the scientific name for "shooting star"?
Correct Answer
C. Meteor
Explanation
A shooting star refers to a bright streak of light that is seen when a small piece of space debris, called a meteoroid, enters the Earth's atmosphere and burns up due to friction. The correct answer is "meteor" because it is the scientific term used to describe this phenomenon. Asteroids are rocky objects that orbit the Sun, comets are icy bodies that also orbit the Sun, and constellations are groups of stars that form patterns in the sky. Therefore, none of these options accurately represent the scientific name for a shooting star.