Chemistry
Which of the following is true about the excess reactant?
A. It is completely consumed in the reaction.
B. It is the reactant that determines the amount of product.
C. Some of it remains after the reaction stops.
D. It limits the reaction from continuing.
C. Some of it remains after the reaction stops.
What is the main function of a power plant?
A. To store electrical energy
B. To convert mechanical energy into electrical energy
C. To produce wind energy
D. To conserve non-renewable resources
B. To convert mechanical energy into electrical energy
Who was the first known astronomer to propose a heliocentric model of the universe?
a. Hipparchus b. Aristarchus c. Ptolemy d. Eratosthenes
b. Aristarchus
Which of the following is an example of vertical motion?
A. A car moving on a straight road
B. A ball dropped from a tall building
C. A person running on a track
D. A paper airplane gliding forward
B. A ball dropped from a tall building
Which surface reflects light the best?
A. Rough and bumpy surfaces
B. Smooth and shiny surfaces
C. Dark and dull surfaces
D. Transparent materials
B. Smooth and shiny surfaces
What happens to the limiting reactant in a chemical reaction?
A. It is completely consumed.
B. It remains after the reaction.
C. It has the highest mass in the reaction.
D. It determines the reaction rate but not the product amount.
A. It is completely consumed.
Which of the following is a renewable energy source?
A. Coal B.Natural Gas
C. Nuclear D. Geothermal
D. Geothermal
. The Ptolemaic System is based on which concept?
A. The Sun as the center of the universe
B. A system of fixed spheres carrying planets around Earth
C. The elliptical orbits of planets
D. The Milky Way as the center of the universe
B. A system of fixed spheres carrying planets around Earth
Which of the following best explains why heavier objects are harder to push?
A. Heavier objects experience more air resistance.
B. Heavier objects have greater inertia.
C. Gravity weakens when pushing heavy objects.
D. Heavy objects have no inertia.
B. Heavier objects have greater inertia.
What is refraction?
A. Light bouncing off a surface
B. Light spreading out in all directions
C. Light bending when it passes through a different material
D. Light stopping when it hits an object
C. Light bending when it passes through a different materia
In the reaction 2A + 3B → 2C, if you start with 4 moles of A and 6 moles of B, what is the limiting reactant?
A. A b. B
C. C d. Cannot be determined
A. A
Which statement best describes the difference between renewable and non-renewable energy sources?
A. Renewable sources are naturally replenished, while non-renewable sources are finite.
B. Renewable energy sources produce more pollution than non-renewable sources.
C. Non-renewable sources are more sustainable in the long run.
D. Non-renewable sources are only used in developing countries.
A. Renewable sources are naturally replenished, while non-renewable sources are finite.
Which of the following was Tycho Brahe’s main contribution to astronomy?
A. He formulated the three laws of planetary motion.
B. He designed the first telescope for astronomical observations.
C. He made extensive celestial observations that helped Kepler develop his laws.
D. He mathematically proved the existence of black holes
C. He made extensive celestial observations that helped Kepler develop his laws.
How does Newton’s First Law expand on Galileo’s idea about motion?
A. Galileo’s ideas only applied to free-falling objects, whereas Newton’s applied to all motion.
B. Newton ignored Galileo’s findings and focused only on acceleration.
C. Newton defined inertia as the tendency of an object to resist changes in its motion.
D. Newton argued that force is always necessary for motion to occur.
C. Newton defined inertia as the tendency of an object to resist changes in its motion.
What is diffraction?
A. Light bending when it enters a new medium
B. Light bouncing off a surface
C. Light spreading out when it passes through a small opening or around an obstacle
D. Light traveling in a straight line only
C. Light spreading out when it passes through a small opening or around an obstacle
Which of the following is an incorrectly balanced equation?
A. CH₄ + 2O₂ → CO₂ + 2H₂O
B. N₂ + 3H₂ → 2NH₃
C. 2KClO₃ → 2KCl + 3O₂
D. H₂ + O₂ → 2H₂O
D. H₂ + O₂ → 2H₂O
What is a major drawback of relying on fossil fuels for energy?
A. They are easily replenished.
B. They do not contribute to pollution.
C. They release greenhouse gases, contributing to climate change.
D. They provide unlimited energy.
C. They release greenhouse gases, contributing to climate change.
How did Galileo challenge Aristotle’s idea of motion?
A. He proposed that objects naturally come to rest.
B. He stated that motion is a natural state and will continue unless interrupted.
C. He claimed that heavier objects fall faster than lighter ones.
D. He suggested that the Earth is the center of the universe.
B. He stated that motion is a natural state and will continue unless interrupted.
Which of the following best explains why Galileo’s ideas on motion were more scientifically accurate than Aristotle’s?
A. Galileo agreed with religious views, making his ideas more accepted.
B. Aristotle’s ideas were later disproven correct by Newton.
C. Galileo used magic and intuition instead of logic.
D. Galileo conducted experiments, while Aristotle relied on philosophical reasoning.
D. Galileo conducted experiments, while Aristotle relied on philosophical reasoning.
How does the particle model explain the reflection of light?
A. Light is made up of tiny particles that bounce off surfaces, following the law of reflection.
B. Light particles slow down when they hit a surface and change direction.
C. Light waves interfere with the particles of the surface, causing reflection.
D. Light is absorbed by the surface and re-emitted in a different direction.
A. Light is made up of tiny particles that bounce off surfaces, following the law of reflection.
Which of the following correctly balances the combustion of methane?
__ CH₄ + __ O₂ → __ CO₂ + __ H₂O
A. CH₄ + O₂ → CO₂ + H₂O
B. CH₄ + 2O₂ → CO₂ + 2H₂O
C. 2CH₄ + O₂ → CO₂ + H₂O
D. CH₄ + O₂ → 2CO₂ + H₂O
B. CH₄ + 2O₂ → CO₂ + 2H₂O
If you were tasked with designing an energy-efficient city, which combination of energy sources would you recommend for long-term sustainability?
A. Coal and petroleum, because they provide consistent energy.
B. Hydropower and solar energy, because they are renewable and reduce environmental impact.
C. Nuclear power and diesel, because they are reliable sources of energy.
D. Biomass and fossil fuels, because they are widely used worldwide.
B. Hydropower and solar energy, because they are renewable and reduce environmental impact.
Why did Kepler’s laws provide better planetary predictions than earlier models?
A. They were based on empirical data rather than assumptions of perfect circles.
B. They were more compatible with religious beliefs at the time.
C. They rejected the idea that the planets orbit the Sun.
D. They relied on philosophical reasoning rather than mathematical evidence.
A. They were based on empirical data rather than assumptions of perfect circles.
Why do objects in a vacuum fall at the same rate, regardless of mass?
A. Because there is no gravitational pull
B. Because air resistance is absent, allowing gravity to act uniformly
C. Because heavier objects exert more force on themselves
D. Because light objects have more energy than heavy ones
B. Because air resistance is absent, allowing gravity to act uniformly
Which of the following correctly describes the wave model of light?
A. Light is made up of particles called photons.
B. Light behaves as a disturbance that travels through space or a medium.
C. Light consists of tiny solid particles that move in straight lines.
D. Light does not travel through a vacuum
B. Light behaves as a disturbance that travels through space or a medium.