Science True or False Questions: 40 Clear Facts and Misconceptions

Question 1

The Sun is a star.

Accepted Answer

True The Sun can feel different from the stars we see at night because it is much closer to Earth, but it belongs to the same broad category: it is a star. Stars are massive balls of hot gas that create energy in their cores. The Sun's energy supports weather, climate, photosynthesis, and nearly all everyday life on Earth. A common mistake is thinking the Sun is a planet because it appears large in the sky. It appears large only because it is close compared with other stars. The Sun is about 150 million kilometers from Earth, a distance often called one astronomical unit. This item checks category confusion: many learners separate the familiar Sun from the more distant stars even though it is one.

Question 2

The Moon makes its own light.

Accepted Answer

False The Moon can look bright enough to light up the night sky, but it is not producing visible light by nuclear fusion or combustion. Its surface reflects sunlight toward Earth. The changing Moon phases happen because we see different portions of the Moon's sunlit side as the Moon orbits Earth. Brightness is not the same as light production. A mirror can look bright in sunlight, but it is reflecting light rather than creating it. Moonlight is reflected sunlight, which is why the Moon's appearance changes with its position relative to Earth and the Sun. This item uses a familiar night-sky observation to separate reflected light from produced light.

Question 3

Earth takes about one year to orbit the Sun.

Accepted Answer

True A day and a year measure different motions. A day is tied to Earth's rotation, while a year is tied to Earth's orbit around the Sun. The exact timing is not a perfect 365 days, which is one reason leap years are used to keep calendars aligned with Earth's orbit. Some people mix up rotation and revolution. Rotation gives us day and night; revolution around the Sun gives us the year. Earth's orbital path is not a perfect circle, but its yearly cycle is regular enough for calendars and seasons.

Question 4

Mars is often called the Red Planet because iron-rich minerals on its surface can look reddish.

Accepted Answer

True The reddish color of Mars is connected to chemistry on its surface. Iron-bearing minerals in Martian dust and rocks can oxidize, producing colors similar to rust on Earth. This does not mean Mars is hot or glowing; it means the surface materials reflect light in a way that looks red or orange to us. A red-looking planet is not necessarily a hot planet. Color can come from surface chemistry, atmosphere, or reflected light. Mars is smaller than Earth and has a much thinner atmosphere.

Question 5

All planets in the solar system are the same size.

Accepted Answer

False The solar system contains rocky planets and gas giants with very different sizes, masses, and compositions. Mercury is small and rocky, Earth is larger and supports liquid surface water, and Jupiter is a massive gas giant. Treating all planets as similar in size hides one of the most important patterns in planetary science. The word planet does not mean a fixed size. It describes a type of object and orbit, not identical dimensions. Jupiter is more than 11 times wider than Earth.

Question 6

A light-year is a unit of distance, not a unit of time.

Accepted Answer

True The name can be confusing because it contains the word year, but a light-year measures distance. Space distances are so large that kilometers or miles quickly become awkward. Saying a star is several light-years away tells us how far light travels to reach us, not how long the star has existed. A light-year is not an age or a calendar year. It is a distance based on the speed of light. Light travels about 9.46 trillion kilometers in one year.

Question 7

A solar eclipse happens somewhere on Earth every single month.

Accepted Answer

False A new moon occurs about once a month, but a solar eclipse requires a more exact alignment of the Sun, Moon, and Earth. Because the Moon's orbit is tilted, the Moon usually passes slightly above or below the Sun from our point of view. Eclipses happen only when the alignment is close enough. It is easy to assume every new moon should block the Sun. The missing piece is orbital tilt. Solar eclipses are predictable because the motions of Earth and the Moon follow regular patterns.

Question 8

Gravity helps keep the Moon in orbit around Earth.

Accepted Answer

True An orbit is a balance between forward motion and gravitational pull. The Moon is constantly being pulled toward Earth by gravity, but it also moves sideways fast enough to keep circling. This same idea helps explain satellites, planets, and many other objects in space. Orbiting does not mean there is no gravity. In fact, gravity is the reason the orbit exists. Astronauts in orbit feel weightless because they are falling around Earth, not because gravity has disappeared.

Question 9

Most stars are located inside our solar system.

Accepted Answer

False The solar system includes the Sun, planets, moons, asteroids, comets, and other smaller objects gravitationally tied to the Sun. The stars visible at night are outside our solar system and are separated from us by enormous distances. This distinction is central to understanding scale in astronomy. Because stars appear in the same sky as planets, people sometimes imagine them as nearby objects. In reality, stars are vastly farther away. The nearest star system beyond the Sun is over four light-years away. This item targets scale confusion, one of the most common beginner astronomy misunderstandings.

Question 10

Mercury is hotter on average than Venus because Mercury is closer to the Sun.

Accepted Answer

False Distance from the Sun matters, but atmosphere matters too. Mercury is closest to the Sun, yet it has almost no atmosphere to hold heat. Venus has a dense atmosphere rich in carbon dioxide, creating an extreme greenhouse effect. That makes Venus the hottest planet on average in the solar system. The closest planet to the Sun is not automatically the hottest in every meaningful sense. Heat retention changes the answer. Venus has surface temperatures hot enough to melt lead.

Question 11

The water cycle includes evaporation, condensation, and precipitation.

Accepted Answer

True The water cycle is not a single event but a repeating system. Water can evaporate from oceans, lakes, soil, and plants; condense into clouds; fall as precipitation; and move again through rivers, groundwater, ice, and living things. This cycle helps connect weather, climate, ecosystems, and human water supplies. A common misconception is that the water cycle only means rain. Rain is just one part of a larger movement of water. The same water molecules can move through the atmosphere, ocean, soil, and living organisms over time.

Question 12

Weather and climate mean exactly the same thing.

Accepted Answer

False Weather is what you experience today or this week: temperature, clouds, wind, rain, and storms. Climate is the long-term pattern of those conditions in a region. A cold day does not disprove a warm climate, and a hot day does not define a climate by itself. Scientists look at patterns over time. People often use weather and climate interchangeably, but the time scale is the key difference. A simple shortcut: weather is what you get today; climate is what is typical over many years.

Question 13

Clouds are made of tiny water droplets, ice crystals, or both.

Accepted Answer

True Although clouds look like soft solid objects from the ground, they are collections of many tiny droplets or ice crystals suspended in air. Their form depends on temperature, humidity, air movement, and altitude. This is why clouds can look thin, puffy, layered, dark, or bright. Clouds are not made of smoke or cotton-like material. They are water in tiny liquid or solid forms. Fog is essentially a cloud that forms near the ground.

Question 14

Earth's crust is the deepest layer of the planet.

Accepted Answer

False Earth is layered. The crust is thin compared with the whole planet and sits on top of the mantle. Farther inside are the outer core and inner core. Understanding this structure helps explain volcanoes, earthquakes, plate tectonics, and Earth's magnetic field. Because we live on the crust, it can feel like the main part of Earth, but it is only the outer shell. Oceanic crust is generally thinner than continental crust.

Question 15

Igneous rocks can form when melted rock cools and hardens.

Accepted Answer

True Igneous rock formation is one part of the rock cycle. When molten rock cools slowly underground, it can form large crystals. When lava cools quickly at the surface, it can form smaller crystals or glassy textures. This process links geology, volcanoes, and Earth's internal heat. Not all rocks form the same way. Igneous, sedimentary, and metamorphic rocks have different formation histories. Granite and basalt are common examples of igneous rocks.

Question 16

Most of Earth's surface is covered by water.

Accepted Answer

True Earth is sometimes called the blue planet because water covers most of its surface. Most of that water is salty ocean water, not fresh water that people can drink directly. This distinction matters for understanding climate, ecosystems, weather patterns, and water resources. Seeing land on maps can make continents feel dominant, but oceans cover the larger share of Earth's surface. Only a small portion of Earth's water is easily available freshwater.

Question 17

Air pressure usually decreases as altitude increases.

Accepted Answer

True Air has weight, and pressure comes from air molecules pressing on surfaces. As altitude increases, there is less atmosphere above a location, so pressure generally decreases. This affects breathing, weather, aircraft, mountain climbing, and even how water boils at high elevations. Air may seem weightless because we do not usually notice it, but the atmosphere exerts pressure all around us. Lower air pressure at high elevation is one reason some people feel short of breath in mountains.

Question 18

Lightning is only produced by heat, not by electrical charge.

Accepted Answer

False Lightning is hot, but heat is not the root cause. It happens when electrical charges build up and discharge between parts of a cloud, between clouds, or between a cloud and the ground. The flash heats the surrounding air very quickly, and the rapid expansion of that air produces thunder. Because lightning looks like fire, some people think it is mainly burning or heat. It is better understood as electricity in the atmosphere. Thunder is the sound created by air rapidly expanding after a lightning flash.

Question 19

Seasons are mainly caused by Earth being much closer to the Sun in summer.

Accepted Answer

False Earth's distance from the Sun changes slightly during the year, but that is not the main cause of seasons. The key factor is Earth's axial tilt. When a hemisphere tilts toward the Sun, it receives more direct sunlight and longer days. When it tilts away, sunlight is less direct and days are shorter. The distance explanation feels intuitive, but it cannot explain why the Northern and Southern Hemispheres have opposite seasons at the same time. Earth is actually closest to the Sun in early January, during Northern Hemisphere winter.

Question 20

Healthy soil is just broken rock and contains no living organisms.

Accepted Answer

False Soil is a living system, not just crushed rock. Mineral particles are important, but soil also contains decayed organic matter, spaces for air and water, plant roots, microbes, fungi, worms, and insects. These parts help recycle nutrients, support plant growth, and store water. A common mistake is treating soil like dirt with no biology. Healthy soil often depends on living organisms. A single handful of healthy soil can contain a large community of microscopic life.

Question 21

Cells are often called the basic units of life.

Accepted Answer

True Cells are the smallest structures that can perform many life processes. Some organisms are made of a single cell, while plants, animals, and fungi are made of many specialized cells. Learning about cells helps explain growth, repair, disease, inheritance, and how living systems function. Cells are not just tiny building blocks like bricks; they are active structures that use energy, exchange materials, and respond to conditions. Bacteria are single-celled organisms, while humans are made of trillions of cells.

Question 22

Plants use photosynthesis to make sugars from light, water, and carbon dioxide.

Accepted Answer

True Photosynthesis is one of the most important processes for life on Earth. Plants, algae, and some bacteria use light energy to build sugar molecules that store energy. The oxygen released during photosynthesis also helps support many living things, including humans and animals. Plants do not simply absorb food from soil. They use light, water, and carbon dioxide to make sugars. Most of the mass a growing plant gains comes from carbon dioxide and water, not from eating soil.

Question 23

All animals make their own food through photosynthesis.

Accepted Answer

False Animals are consumers, not producers. They cannot use sunlight to make sugars the way plants and algae do. Instead, animals obtain energy and materials by eating. Even animals that live with photosynthetic organisms still rely on food or partnerships rather than doing plant-like photosynthesis themselves. Because some animals are green or live near plants, it is easy to overextend the idea of photosynthesis. In basic biology, animals get energy by consuming. Food webs connect producers, consumers, and decomposers through energy flow.

Question 24

An ecosystem includes living organisms and the nonliving parts of their environment.

Accepted Answer

True Ecosystems are not only lists of organisms. They include relationships among living things and the nonliving conditions around them. A pond ecosystem, for example, includes fish, algae, bacteria, water, light, temperature, oxygen, mud, and nutrients. Changing one part can affect many others. People often think an ecosystem means only animals and plants. The nonliving environment is part of the system too. Ecosystems can be large like forests or small like a rotting log community.

Question 25

In a food chain, energy usually starts with producers such as plants or algae.

Accepted Answer

True A simple food chain shows how energy moves from one organism to another. Producers such as plants and algae capture energy and make food. Herbivores, carnivores, omnivores, and decomposers then use energy from other organisms. Real ecosystems are usually food webs rather than perfectly simple chains. A predator at the top of a food chain is not the original source of energy. Producers are usually the starting point. Energy is lost as heat at each step in a food chain, so shorter chains transfer energy more efficiently.

Question 26

The heart's main job is to digest food.

Accepted Answer

False The heart is part of the circulatory system. It moves blood through vessels so oxygen, nutrients, hormones, and waste products can be transported. Digestion involves organs such as the stomach, intestines, liver, and pancreas. Separating body systems helps explain how organs work together without confusing their primary roles. Because blood carries nutrients from digested food, people may confuse circulation with digestion. The heart transports; it does not digest. The heart beats many times per minute to keep blood moving through the body.

Question 27

DNA carries genetic information in living things.

Accepted Answer

True DNA is a molecule that carries genetic information. Its sequence helps guide how cells build proteins and regulate many biological processes. While genes influence traits, most traits also depend on development, environment, and interactions among many genes, so DNA is important without being a simple one-gene-one-trait script for everything. DNA is not a visible trait by itself. It is an information-carrying molecule that affects how living things develop and function. The letters often used for DNA bases are A, T, C, and G.

Question 28

A habitat means only the food an organism eats.

Accepted Answer

False Food is important, but it is only one part of a habitat. A good habitat must also provide physical conditions and resources that allow an organism to survive and reproduce. For example, a frog may need insects for food, water for reproduction, shelter from predators, and suitable temperatures. Habitat is broader than diet. Diet describes what an organism eats; habitat describes where and how it lives. Habitat loss can harm species even when some food is still available.

Question 29

Decomposers permanently remove nutrients from ecosystems.

Accepted Answer

False Decomposers such as fungi and bacteria break down organic matter and return nutrients to soil, water, or other parts of an ecosystem. Without decomposers, dead material would accumulate and nutrients would become locked away. Decomposition is one reason ecosystems can keep reusing materials over time. Decomposition can look like disappearance, but the matter is being changed and recycled, not simply erased. Fungi are major decomposers in many forests.

Question 30

An adaptation is always a behavior and never a body feature.

Accepted Answer

False Adaptations are inherited features or behaviors shaped by natural selection over generations. Thick fur, camouflage, beak shape, migration, and drought tolerance can all be adaptations. The important point is not whether the trait is physical or behavioral, but whether it helps organisms survive and reproduce in a particular environment. Some learners think adaptations are choices an individual makes. In biology, adaptations are usually population-level traits shaped over generations. A trait that helps in one environment may be less useful or even harmful in another.

Question 31

Matter is anything that has mass and takes up space.

Accepted Answer

True Matter is the physical material of the world around us. A rock, a glass of water, air in a balloon, and glowing plasma are all examples of matter in different forms. Understanding matter helps connect chemistry, physics, biology, and Earth science because all everyday objects are made of matter. Air can be overlooked because it is invisible, but it still has mass and takes up space. A balloon weighs slightly more when filled with air because air has mass.

Question 32

Water can exist as a solid, liquid, or gas under common Earth conditions.

Accepted Answer

True Water is a familiar example of matter changing state. At low temperatures it can freeze into solid ice, at moderate conditions it can be liquid, and with enough energy it can evaporate or boil into water vapor. These state changes are physical changes because the substance is still water. Water vapor is not the same as visible steam clouds. True water vapor is a gas and is usually invisible. The freezing and boiling points of water can change with pressure.

Question 33

Atoms are made only of cells.

Accepted Answer

False Cells are much larger biological structures made from many molecules, and molecules are made from atoms. Atoms belong to chemistry and physics, while cells belong to biology. Keeping these levels of organization separate helps prevent confusion between living structures and the particles that make up all matter. The order matters: atoms form molecules, molecules help build cell structures, and cells make up living organisms. A single cell contains many different kinds of atoms arranged in complex molecules.

Question 34

Energy disappears when it is used.

Accepted Answer

False In everyday language, people say energy is used up, but physics describes energy as changing form or moving from place to place. A battery powering a flashlight transfers chemical energy into electrical energy, light, and heat. The useful energy may become less available for the task, but it has not vanished. Used up is a practical phrase, not a literal science description. The energy usually becomes spread out or converted into less useful forms. Energy conservation is one of the central ideas in physics.

Question 35

A force can change an object's speed, direction, or shape.

Accepted Answer

True Forces explain many everyday events: kicking a ball, braking a bicycle, stretching a rubber band, or turning a car. A force does not always make something move immediately; balanced forces can cancel each other. But when forces are unbalanced, an object's motion or shape can change. A force is not only something that starts motion. It can also stop, turn, squeeze, stretch, or balance an object. Gravity, friction, tension, and magnetism are examples of forces.

Question 36

Every material is strongly attracted to a magnet.

Accepted Answer

False Magnets interact strongly with certain materials, but not with all materials. Paper, wood, plastic, glass, and many metals are not strongly attracted to ordinary magnets. Magnetic behavior depends on the material's atomic structure and how tiny magnetic regions are arranged. A metal object is not automatically magnetic. Aluminum and copper are metals, but they are not strongly attracted to common magnets. Iron is one of the best-known magnetic materials.

Question 37

A chemical reaction forms new substances.

Accepted Answer

True Chemical reactions are different from simple changes in shape or state. Burning, rusting, cooking an egg, and vinegar reacting with baking soda involve atoms rearranging into new combinations. The signs of a reaction can include gas formation, color change, temperature change, light, or a new solid, but evidence should be interpreted carefully. Not every visible change is a chemical reaction. Melting ice changes state, but the substance is still water. Chemical equations show reactants changing into products.

Question 38

Density means exactly the same thing as weight.

Accepted Answer

False Density and weight are related to matter, but they are not the same. A small metal cube can be denser than a large foam block even if the foam block weighs more overall. Density helps explain floating, sinking, layering of liquids, and why objects with the same size can feel very different in heaviness. Heavier does not always mean denser. Size and volume matter when comparing density. Density is commonly calculated as mass divided by volume.

Question 39

Sound needs a medium such as air, water, or a solid to travel.

Accepted Answer

True Sound is a mechanical wave. It moves by causing particles in a medium to vibrate and pass that vibration along. Sound can travel through gases, liquids, and solids, but it cannot travel through a perfect vacuum in the ordinary way. This is why space scenes with loud explosions are not realistic as sound in open space. Movies often make space sound loud for dramatic effect, but real sound needs matter to carry vibrations. Sound usually travels faster in solids than in air because particles are closer together.

Question 40

White light contains only one color.

Accepted Answer

False White light looks plain to our eyes, but it can contain many wavelengths of visible light. A prism bends different wavelengths by different amounts, spreading them into colors. Rainbows form by a related process as sunlight is refracted, reflected, and dispersed by water droplets in the air. White does not always mean simple or single. In light, white often means a mixture of visible wavelengths. The colors of a rainbow appear because different wavelengths of light bend differently.