Solar System Models
Which model of the solar system places Earth at the center, with the Sun and planets revolving around it?
A. Heliocentric model
B. Geocentric model
C. Modern model
D. Nebular model
B. Geocentric Model
Geo - Earth & centric - centered
Which force keeps the planets moving in orbits around the Sun?
A. Magnetic force
B. Gravitational force
C. Frictional force
D. Electrical force
B. Gravitational Force
The Sun's gravity keeps the planets in orbit.
Which statement correctly describes mass?
A. The amount of matter in an object
B. The force of gravity on an object
C. The speed at which an object falls
D. The distance an object is from a planet
A. The amount of matter in an object
Mass measures how much matter an object contains.
Which planet would generally have a longer revolution period around the Sun?
A. A planet closer to the Sun
B. A planet farther from the Sun
C. A planet with a thinner atmosphere
D. A planet with fewer moons
B. A planet farther from the Sun
Planets farther from the Sun generally take longer to complete an orbit.
Which statement best explains why scientific theories may change over time?
A. Theories change whenever scientists disagree.
B. Theories change when new evidence improves our understanding.
C. Theories automatically become laws over time.
D. Theories change because they are based only on opinions.
B. Theories change when new evidence improves our understanding.
Reliable new evidence can lead scientists to improve or modify theories.
Which statement best describes the heliocentric model?
A. Earth is stationary at the center.
B. The Moon is the center of the solar system.
C. The Sun is at the center, and planets revolve around it.
D. Planets do not move around the Sun.
C. The Sun is at the center, and planets revolve around it
Helio - Sun & Centric - centered
Two objects are moved farther apart without changing their masses. What happens to the gravitational force between them?
A. It increases.
B. It stays the same.
C. It decreases.
D. It disappears completely.
C. It decreases
Gravitational attraction becomes weaker as distance increases.
A person travels from Earth to the Moon, where gravity is weaker. What happens to the person's weight?
A. It increases.
B. It decreases.
C. It stays the same.
D. It becomes equal to their mass.
B. It decreases
Weight decreases because the Moon's gravity is weaker.
Venus has a much thicker atmosphere than Mercury. How does this help explain their temperatures?
A. Venus has a thick atmosphere that traps heat.
B. Mercury's thin atmosphere traps more heat.
C. Venus receives more sunlight because it is closer.
D. Mercury stays hotter because it has more moons.
A. Venus has a thick atmosphere that traps heat.
Venus's dense atmosphere traps heat, making its surface extremely hot.
What was the solar system originally formed from?
A. A cloud of gas and dust called a nebula
B. A group of fully formed planets
C. Pieces of an already formed Sun
D. A collection of moons orbiting Earth
A. A cloud of gas and dust called a nebula
Our solar system formed from a cloud of gas and dust.
What is one major difference between the early heliocentric model and the modern model?
A. The modern model places Earth at the center.
B. The modern model shows elliptical instead of circular planetary orbits.
C. The modern model shows the Sun orbiting Earth.
D. The modern model removes gravity from planetary motion.
B. The modern model shows elliptical instead of circular planetary orbits
Two spheres are the same distance apart. The mass of one sphere is increased. How does this affect the gravitational force between them?
A. The force increases.
B. The force decreases.
C. The force remains the same.
D. The force changes direction.
A. The force increases.
Increasing mass increases the gravitational attraction between the objects.
A scientist measures a rock's mass as 8 kg on Earth. What would its mass be if the rock were taken to Mars?
A. Less than 8 kg
B. More than 8 kg
C. 8 kg
D. 0 kg
C. 8 kg
Mass does not change when an object moves between planets.
Which property is most helpful when explaining why Neptune's year is much longer than Mars's year?
A. Number of moons
B. Thickness of atmosphere
C. Distance from the Sun
D. Length of rotation
C. Distance from the Sun
Neptune orbits much farther from the Sun, so its revolution period is longer.
Which statement best describes the order in which the solar system formed?
A. The planets formed, followed by the nebula and Sun.
B. The Sun formed before the nebula existed.
C. A nebula collapsed, the Sun formed, and leftover matter formed planets.
D. The planets formed first, then gravity pulled them into the Sun.
C. A nebula collapsed, the Sun formed, and leftover matter formed planets.
Gravity caused the nebula to collapse. The Sun formed at the center, and remaining material formed the planets.
Scientists observe that Earth rotates on its axis and revolves around the Sun. Which model best explains these observations?
A. Geocentric model
B. Earth-centered model
C. A model with stationary planets
D. Heliocentric model
D. Heliocentric model
Two satellites of equal mass are orbiting Earth. Satellite A orbits closer to Earth than Satellite B. Which statement is correct?
A. Satellite B experiences stronger gravity because it is farther away.
B. Both satellites experience exactly the same gravitational force.
C. Satellite A experiences weaker gravity because it is closer.
D. Satellite A experiences stronger gravity because it is closer.
D. Satellite A experiences stronger gravity because it is closer.
At the closer distance, Earth's gravitational pull is stronger.
A metal container is moved from Earth to a planet with stronger surface gravity. Which statement correctly describes what happens?
A. Both mass and weight increase.
B. Mass increases, but weight stays the same.
C. Both mass and weight remain the same.
D. Mass stays the same, but weight increases.
D. Mass stays the same, but weight increases.
Mass remains constant; weight increases when gravitational pull is stronger.
Why are the inner planets mostly rocky while the outer planets contain much more gas and ice?
A. The inner planets formed farther from the Sun.
B. The outer planets formed before gravity existed.
C. The inner planets have more moons.
D. Cooler conditions farther from the Sun allowed ice and gases to collect.
D. Cooler conditions farther from the Sun allowed ice and gases to collect.
Conditions were hotter near the Sun and cooler farther away, affecting the materials planets formed from.
Which statement best explains how a planet maintains its round shape and stays in orbit around the Sun?
A. Its magnetic field makes it round and keeps it in orbit.
B. Nearby moons make it round and push it around the Sun.
C. Its rotation makes it round, and friction holds it in orbit.
D. Its own gravity pulls matter inward, while the Sun's gravity keeps it in orbit.
D. Its own gravity pulls matter inward, while the Sun's gravity keeps it in orbit.
A planet's self-gravity makes large planets nearly spherical, and solar gravity maintains their orbits.
A student draws a model with the Sun at the center and planets moving in perfect circles. Which model does this best represent, and what should be changed to make it more accurate?
The early heliocentric model.
Change circular orbits to elliptical (oval-shaped) orbits.
A cloud of gas and dust began collapsing billions of years ago. Explain how gravity helped form the Sun and later the planets.
Gravity pulled gas and dust together, forming the Sun at the center. The leftover matter collided and stuck together, eventually forming planets.
A bowling ball and a tennis ball are resting on Earth. Why does the bowling ball weigh more even though both are affected by Earth's gravity?
The bowling ball has more mass, so Earth's gravity pulls on it with a greater force.
At the same location, an object with greater mass experiences greater weight.
A spacecraft visits two planets. Planet A is small, rocky, and has a thin atmosphere. Planet B is very large and contains mostly gas and ice. Which is more likely an inner planet, and why?
Planet A, because inner planets are smaller, rocky, and generally have thinner atmospheres.
Why are scientific theories usually modified rather than completely discarded when new evidence is discovered?
Scientific theories are supported by strong evidence. New evidence can help scientists improve or update a theory rather than completely throw it out.