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OST Grade 5 Science study materials
OST Grade 5 Science study resources

OST Grade 5 Science practice questions

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Question 1Earth and Space Science

Which layer of Earth is made mostly of solid iron and nickel and lies at the very center?

  1. The inner core Correct answer.
  2. The outer core
  3. The crust
  4. The mantle

Explanation

Earth's center is the inner core, where very high pressure keeps iron and nickel solid despite extreme heat. The outer core is also iron-rich but is liquid, and the mantle and crust are made of rocky silicate material.

Question 2Earth and Space Science

A student observes that water left in an open cup disappears over several days. Which process best explains this?

  1. Runoff, because water flows downhill over land
  2. Condensation, because water vapor cools into droplets
  3. Evaporation, because liquid water gains energy and becomes water vapor Correct answer.
  4. Precipitation, because water falls from clouds

Explanation

Evaporation changes liquid water into water vapor when molecules gain enough energy to escape the surface. In an open cup, that vapor mixes with the air and the water level drops. The other processes describe vapor turning to liquid or water moving as rain or flow.

Question 3Earth and Space Science

Which statement correctly describes how Earth moves in space?

  1. Earth rotates on its axis once about every 24 hours and orbits the Sun once about every 365 days. Correct answer.
  2. Earth stays still while the Sun and Moon orbit around it each day.
  3. Earth rotates on its axis once about every 365 days and orbits the Sun once about every 24 hours.
  4. Earth orbits the Moon once about every 24 hours and rotates on its axis once about every month.

Explanation

Earth spins on its tilted axis once per day, producing the cycle of day and night. At the same time it travels around the Sun once per year, about 365 days, which drives the seasons.

Question 4Earth and Space Science

The Sun appears to rise in the east and set in the west each day. What actually causes this apparent motion?

  1. The Sun orbiting Earth once each day
  2. Earth rotating from west to east on its axis Correct answer.
  3. The Moon pulling the Sun across the sky
  4. Earth orbiting the Sun once each day

Explanation

Earth turns from west to east, so objects in the sky seem to move the opposite way, from east to west. The Sun's apparent daily path is therefore a result of Earth's rotation, not of the Sun circling Earth.

Question 5Earth and Space Science

Which property of soil is most directly tested by squeezing a moist sample to see whether it holds together in a ball?

  1. Its ability to stick together, which relates to clay and silt content Correct answer.
  2. Its color, which relates to the minerals it contains
  3. Its mass, which relates to the size of the sample
  4. Its temperature, which relates to sunlight exposure

Explanation

A soil squeeze test shows how well particles bind, which depends on the amount of fine clay and silt. Sandy soil crumbles because its larger particles do not pack tightly. Color, temperature, and mass do not describe how soil holds together.

Question 6Earth and Space Science

A rock sample contains visible layers and a fossil of a fish. Which type of rock is it most likely to be?

  1. A pure mineral crystal
  2. Sedimentary rock Correct answer.
  3. Igneous rock
  4. Metamorphic rock

Explanation

Sedimentary rock forms from layers of sediment that build up and harden over time, and fossils are commonly preserved in those layers. Igneous rock forms from cooled magma or lava, and metamorphic rock forms when existing rock is changed by heat and pressure.

Question 7Earth and Space Science

Which of these is a renewable energy resource that comes directly from the Sun?

  1. Natural gas pumped from wells
  2. Petroleum refined into fuel
  3. Coal mined from the ground
  4. Solar energy collected by panels Correct answer.

Explanation

Solar panels convert sunlight into electricity, and sunlight is continually replaced, so it is renewable. Coal, natural gas, and petroleum are fossil fuels formed over millions of years and are used up faster than they form.

Question 8Earth and Space Science

Which tool would a student use to measure the amount of rain that fell during a storm?

  1. An anemometer
  2. A thermometer
  3. A rain gauge Correct answer.
  4. A barometer

Explanation

A rain gauge collects rainfall and has markings that show depth in millimeters or inches. Thermometers measure temperature, anemometers measure wind speed, and barometers measure air pressure.

Question 9Earth and Space Science

A valley glacier slowly moves down a mountain. Which evidence would best show that the glacier once covered a nearby area?

  1. Round sand grains piled at the bottom of a river
  2. Tree rings that are wider in wet years
  3. Fossils of ocean shells on a mountain peak
  4. Scratches and polished rock surfaces along the valley walls Correct answer.

Explanation

As a glacier moves, rocks frozen into its base scrape and polish the bedrock beneath it, leaving long scratches called striations. These marks remain after the ice melts and indicate where a glacier has been. The other choices are caused by water, plant growth, or past ocean coverage.

Question 10Earth and Space Science

Warm air rises while cooler, denser air sinks. How does this movement most directly affect weather?

  1. It causes Earth's magnetic field to reverse.
  2. It creates convection currents that form clouds and wind. Correct answer.
  3. It stops all wind from blowing near the ground.
  4. It makes the Moon change phases.

Explanation

Uneven heating makes warmer, less dense air rise and cooler air sink, setting up convection currents. Rising moist air cools, and its vapor condenses into cloud droplets, while the horizontal movement of air is wind. Magnetic reversals and Moon phases are unrelated to air convection.

Question 11Earth and Space Science

A weather map shows a cold front moving toward a town. Which change in weather is most likely as the front arrives?

  1. A sudden drop in temperature with heavy rain or thunderstorms Correct answer.
  2. A change in wind direction with no change in temperature
  3. A slow warming with clear, dry skies for many days
  4. A steady rise in temperature with no clouds

Explanation

At a cold front, a mass of cold air pushes under warm, moist air, forcing it up quickly. This rapid lifting produces tall storm clouds, heavy rain or thunderstorms, and a temperature drop after the front passes.

Question 12Earth and Space Science

The Moon's shape as seen from Earth changes in a repeating pattern about every 29 days. What causes these changes?

  1. The changing angle at which we see the Moon's sunlit half as it orbits Earth Correct answer.
  2. The Moon spinning quickly on its axis each day
  3. Earth's shadow falling on the Moon every night
  4. Clouds blocking different parts of the Moon

Explanation

Half of the Moon is always lit by the Sun, but as the Moon orbits Earth we see different amounts of that lit half, producing the phases. Earth's shadow causes eclipses, which are rare, not the monthly cycle.

Question 13Earth and Space Science

Which statement best explains why the seasons occur on Earth?

  1. Earth spins faster in summer, making the days longer.
  2. The Sun gives off more heat in summer than in winter.
  3. Earth is much closer to the Sun in summer and much farther away in winter.
  4. Earth's axis is tilted, so sunlight strikes each hemisphere at different angles during the year. Correct answer.

Explanation

Earth's axis is tilted about 23.5 degrees, so as Earth orbits the Sun each hemisphere receives sunlight at a steeper angle and for more hours during its summer. Distance from the Sun changes only slightly and cannot explain opposite seasons in the two hemispheres.

Question 14Earth and Space Science

A student compares two soil samples. Sample A drains water quickly and feels gritty; Sample B holds water and feels smooth and sticky. Which conclusion is best supported?

  1. Sample A has more clay, and Sample B has more sand.
  2. Sample A has more sand, and Sample B has more clay. Correct answer.
  3. Sample A contains more humus than Sample B.
  4. Both samples have the same texture but different colors.

Explanation

Sand particles are large, so water passes through quickly and the soil feels gritty. Clay particles are tiny and pack closely, holding water and feeling smooth and sticky. These observations support the texture difference between the two samples.

Question 15Earth and Space Science

Which sequence correctly orders the formation of a sedimentary rock from loose sediment?

  1. Cementation, melting, deposition
  2. Deposition, compaction, cementation Correct answer.
  3. Weathering, melting, compaction
  4. Melting, cooling, deposition

Explanation

Sediment is first deposited in layers, then buried and squeezed by compaction, and finally glued together by minerals in a process called cementation. Melting and cooling describe the formation of igneous rock, not sedimentary rock.

Question 16Earth and Space Science

A town installs solar panels and wind turbines to replace a coal-burning power plant. Which is the most likely benefit of this change?

  1. A permanent end to all electricity costs
  2. Faster formation of new coal deposits
  3. Less air pollution and a reduced release of carbon dioxide Correct answer.
  4. Guaranteed electricity on calm, cloudy days without storage

Explanation

Solar and wind power generate electricity without burning fuel, so they release little or no carbon dioxide or air pollutants during operation. They can still be limited by weather, so backup storage or other sources may be needed.

Question 17Earth and Space Science

A scientist records the height of a shadow cast by a stick at noon each day for a year. The shadow is shortest in June and longest in December. What does this pattern most directly show?

  1. The Sun moves closer to Earth in December.
  2. Earth stops rotating in June.
  3. The stick changes length with the seasons.
  4. The Sun's apparent height in the sky changes through the year. Correct answer.

Explanation

A shorter noon shadow means the Sun is higher in the sky, which happens when the Sun's rays strike more directly. The yearly change in the Sun's apparent height is caused by Earth's tilted axis as it orbits the Sun.

Question 18Earth and Space Science

A river carries sand and mud downstream and drops them where the current slows at a lake. Over many years, what is most likely to form at that spot?

  1. A volcano of erupted lava
  2. A cave carved by dissolving rock
  3. A delta of deposited sediment Correct answer.
  4. A glacier of compacted ice

Explanation

When a river slows as it enters a lake or ocean, it can no longer carry as much sediment, so the material settles out. Repeated deposition builds a delta, a fan-shaped area of new land at the river's mouth.

Question 19Earth and Space Science

A student builds a model showing Earth, the Moon, and the Sun in a straight line with the Moon between Earth and the Sun. Which event could this model represent?

  1. A spring tide only
  2. A full moon
  3. A solar eclipse Correct answer.
  4. A lunar eclipse

Explanation

A solar eclipse occurs when the Moon passes directly between Earth and the Sun and blocks sunlight from reaching part of Earth. A lunar eclipse happens when Earth is between the Sun and the Moon.

Question 20Earth and Space Science

A region receives heavy rain on a steep hillside where plants have been removed. Which result is most likely?

  1. No change, because plant roots do not affect soil
  2. Faster erosion because roots no longer hold the soil in place Correct answer.
  3. Increased soil formation because rain adds new soil
  4. Slower erosion because bare soil absorbs more water

Explanation

Plant roots anchor soil and slow the flow of water across the surface. When plants are removed on a steep slope, rainwater can wash soil downhill quickly, increasing erosion. Rain does not create new soil during a single storm.

Question 21Earth and Space Science

A student reads that a certain fossil shell is found in rock layers high in the mountains. Which conclusion is best supported by this evidence?

  1. The fossil was carried up by wind after the mountain formed.
  2. The area was once covered by water, and the rock layers were later pushed upward. Correct answer.
  3. The mountain formed from a volcano that erupted shells.
  4. The shell animal climbed the mountain and died there.

Explanation

Marine shells form in water, so their presence in mountain rock indicates that the layers were deposited underwater and later uplifted by Earth's moving plates. Wind or animals could not plausibly move shells into solid rock at high elevation.

Question 22Earth and Space Science

Two cities are at the same latitude, but one is near the coast and the other is far inland. Which difference in climate is most likely?

  1. The coastal city is always colder because ocean water is always frozen.
  2. The inland city has smaller temperature swings because land heats and cools more slowly than water.
  3. The coastal city has smaller temperature swings because water heats and cools more slowly than land. Correct answer.
  4. Both cities have identical temperatures because latitude controls climate completely.

Explanation

Water has a higher heat capacity than land, so it absorbs and releases heat more slowly. A coastal city is therefore warmed by the ocean in winter and cooled by it in summer, giving smaller seasonal temperature swings than an inland city.

Question 23Earth and Space Science

A city replaces dark asphalt roofs with white reflective roofs. How could this change affect the local temperature?

  1. It would change the direction of Earth's rotation.
  2. It would have no effect because roof color does not interact with sunlight.
  3. It could raise local temperatures because white surfaces absorb more heat.
  4. It could lower local temperatures because more sunlight is reflected instead of absorbed. Correct answer.

Explanation

Dark surfaces absorb more solar energy and release it as heat, warming the surrounding air. Lighter, reflective surfaces bounce more sunlight back, so less heat is absorbed and local temperatures can drop. Roof color cannot affect Earth's rotation.

Question 24Earth and Space Science

A student compares the amount of water in a closed terrarium and an open terrarium over two weeks. The open one loses water while the closed one stays nearly the same. Which explanation is best?

  1. The closed terrarium prevents water from changing state at all.
  2. The closed terrarium creates new water through condensation.
  3. The closed terrarium traps water vapor so it condenses and returns as liquid, while the open one lets vapor escape. Correct answer.
  4. The open terrarium has no evaporation because it is open to air.

Explanation

In a closed system, evaporated water vapor condenses on the walls and lid and drips back, so total water stays nearly constant. In an open system, vapor escapes into the surrounding air and the water supply drops. Condensation moves water but does not create it.

Question 25Earth and Space Science

A layer of sedimentary rock contains older fossils near the bottom and younger fossils near the top. Which principle explains this pattern?

  1. Fossils move upward through rock as they age.
  2. Rock layers form all at once with no order.
  3. Younger layers are always deposited underneath older ones.
  4. In undisturbed layers, lower layers were deposited first and are older. Correct answer.

Explanation

The principle of superposition states that in undisturbed sedimentary layers, the oldest layers are at the bottom because they were deposited first. Younger sediment settles on top later, so fossils in upper layers are younger.

Question 26Earth and Space Science

Which layer of Earth is made mostly of solid iron and nickel and lies at the center?

  1. The outer core
  2. The mantle
  3. The inner core Correct answer.
  4. The crust

Explanation

Earth's center is the inner core, where extreme pressure keeps iron and nickel solid despite very high temperatures. The layers around it differ in composition and state, which is why geologists separate them.

Question 27Earth and Space Science

A student's model of Earth's layers uses a hard-boiled egg cut in half. Which part of the egg best represents Earth's thin outer crust?

  1. The round yolk
  2. The thick white
  3. The air pocket
  4. The thin shell Correct answer.

Explanation

The crust is a thin, rigid outer layer compared with the much thicker layers beneath it. The eggshell is the only part of the model that is a thin outer covering, so it matches the crust's position and relative thinness.

Question 28Earth and Space Science

Which process slowly breaks solid rock into smaller pieces when water freezes inside cracks?

  1. Deposition
  2. Frost wedging Correct answer.
  3. Compaction
  4. Melting

Explanation

Water expands when it freezes, so ice in a rock crack pushes the rock apart; repeated freeze-thaw cycles split it. This is a form of physical weathering because the rock's material does not change chemically.

Question 29Earth and Space Science

Which of these is the best example of erosion rather than weathering?

  1. Iron in a rock rusting and turning crumbly
  2. A rock cracking as ice expands in a crack
  3. A stream carrying loose sand grains downstream Correct answer.
  4. A cliff face being broken apart by plant roots

Explanation

Erosion is the transport of weathered material from one place to another, so moving sand grains downstream is erosion. The other choices describe the breakdown of rock in place, which is weathering.

Question 30Earth and Space Science

Wind blows sand across a desert and piles it into mounds with a gentle slope on the windward side and a steep slope on the leeward side. What are these mounds called?

  1. Sand dunes Correct answer.
  2. Floodplains
  3. Moraines
  4. Deltas

Explanation

Sand dunes form when wind deposits sand, and their shape records the wind direction, with a gentle windward slope and a steeper slip face. Deltas, moraines, and floodplains are built by water or glaciers instead.

Question 31Earth and Space Science

Which statement best describes how a canyon can be carved by a river over a long time?

  1. The river channel widens because the ground beneath it melts
  2. Melted rock flows down the slope and cools into a deep channel
  3. Wind blows loose rock into the river channel from the canyon walls
  4. Flowing water wears away rock and carries the loosened pieces away Correct answer.

Explanation

A river erodes its bed and banks by abrasion and by lifting loose material, then transports that material downstream. Repeated over a long period, this cutting deepens and widens a canyon.

Question 32Earth and Space Science

A landslide carries soil down a steep slope and piles it at the bottom. Which term names the downhill movement of rock and soil caused by gravity?

  1. Precipitation
  2. Condensation
  3. Evaporation
  4. Mass wasting Correct answer.

Explanation

Mass wasting is the downslope movement of rock, soil, and debris under the pull of gravity. Landslides, mudflows, and creep are all types of mass wasting.

Question 33Earth and Space Science

A student builds a model of a volcano and adds baking soda and vinegar inside it. What does the overflowing foam represent?

  1. Rain soaking into the soil
  2. Wind carrying volcanic ash
  3. Lava erupting onto the surface Correct answer.
  4. Groundwater dissolving limestone

Explanation

The foam stands for magma that reaches the surface, where it is called lava. A model is useful when it captures the key process, here the rising and overflowing of molten rock.

Question 34Earth and Space Science

Two tectonic plates slide past each other along a fault. Which event is most likely when stress builds up and is suddenly released?

  1. An earthquake Correct answer.
  2. A drought
  3. A tsunami caused by wind
  4. A hurricane

Explanation

When plates slide past each other, friction can lock the fault until stress overcomes it and the rock breaks or slips, releasing energy as seismic waves. That sudden release is an earthquake.

Question 35Earth and Space Science

A map shows a boundary where two plates are moving apart and new ocean floor is forming. Which type of boundary is this?

  1. Subduction zone
  2. Convergent boundary
  3. Divergent boundary Correct answer.
  4. Transform boundary

Explanation

At a divergent boundary, plates move apart and magma rises to fill the gap, creating new crust such as the mid-ocean ridge. Convergent and transform boundaries involve plates moving together or sliding past each other.

Question 36Earth and Space Science

Fossils of similar land animals are found on two continents now separated by a wide ocean. Which explanation best fits this evidence?

  1. The fossils were carried by ocean currents
  2. Both continents formed from the same volcano
  3. The continents were once joined and later moved apart Correct answer.
  4. The animals swam across the ocean many times

Explanation

Land animals cannot cross a wide ocean, so their fossils on separate continents suggest the landmasses were once connected. Plate motion later carried the continents apart, which is strong evidence for continental drift.

Question 37Earth and Space Science

Which property of a mineral is tested by scratching it against a series of known reference materials?

  1. Magnetism
  2. Streak color
  3. Hardness Correct answer.
  4. Cleavage

Explanation

Hardness is a mineral's resistance to being scratched, and it is compared using reference materials of known hardness. Streak, magnetism, and cleavage are tested in other ways.

Question 38Earth and Space Science

A mineral leaves a white powder when rubbed across an unglazed porcelain plate, even though the mineral itself looks dark gray. Which property was just tested?

  1. Streak Correct answer.
  2. Density
  3. Luster
  4. Hardness

Explanation

Streak is the color of a mineral's powder, and it can differ from the color of the whole sample. Rubbing the mineral on unglazed porcelain is the standard streak test.

Question 39Earth and Space Science

A rock forms when magma cools slowly deep underground, producing large crystals. Which rock type is it?

  1. Metamorphic rock
  2. Extrusive igneous rock
  3. Sedimentary rock
  4. Intrusive igneous rock Correct answer.

Explanation

Slow cooling beneath the surface allows crystals to grow large, which is characteristic of intrusive igneous rock. Extrusive rock cools quickly at the surface and has small crystals.

Question 40Earth and Space Science

Limestone is buried deep underground and changed by intense heat and pressure without melting. What kind of rock does it become?

  1. Metamorphic rock Correct answer.
  2. Volcanic glass
  3. Sedimentary rock
  4. Igneous rock

Explanation

Heat and pressure can change a rock's minerals and texture without melting it, producing metamorphic rock. If it melted, it would cool into igneous rock instead.

Question 41Earth and Space Science

Which statement best explains why the rock cycle has no true beginning or end?

  1. Each rock type can form only once and then stays the same
  2. All rocks form at the same time and never change afterward
  3. Rocks only change when people break them apart
  4. Any rock type can be changed into another by processes such as melting, weathering, and heat Correct answer.

Explanation

The rock cycle is a set of ongoing processes: weathering and deposition build sediment, heat and pressure cause metamorphism, and melting produces magma that cools into igneous rock. Because any type can be transformed into any other, the cycle has no fixed starting point.

Question 42Earth and Space Science

Which statement best explains why ocean water is salty while most rainwater is not?

  1. Rocks on land release dissolved minerals that rivers carry to the ocean, where the water evaporates and leaves salts behind Correct answer.
  2. Ocean animals produce all of the salt found in seawater
  3. Rainwater already contains the same amount of salt as ocean water
  4. Salt forms in the ocean from sunlight striking the water

Explanation

Weathering releases ions such as sodium and chloride from rock, and rivers transport them to the ocean. Evaporation removes water as vapor but leaves dissolved salts behind, so salts accumulate over time.

Question 43Earth and Space Science

What causes most ocean tides on Earth?

  1. The rotation of Earth's solid inner core
  2. The melting of glaciers each summer
  3. Strong winds blowing across the sea surface
  4. The gravitational pull of the Moon and, to a lesser degree, the Sun Correct answer.

Explanation

The Moon's gravity pulls most strongly on the water nearest it, creating a bulge, while the Sun's gravity adds a smaller effect. Earth's rotation carries locations through these bulges, producing two high tides and two low tides most days.

Question 44Earth and Space Science

Which process is the main way water moves from the ocean into the atmosphere?

  1. Runoff flowing down rivers
  2. Evaporation driven by energy from the Sun Correct answer.
  3. Condensation inside clouds
  4. Precipitation falling as rain

Explanation

Solar energy heats surface water and turns it into vapor, which rises into the atmosphere. Condensation, runoff, and precipitation move water in other parts of the cycle.

Question 45Earth and Space Science

Water vapor cools high in the atmosphere and forms tiny droplets around dust particles. Which step of the water cycle is this?

  1. Evaporation
  2. Transpiration
  3. Infiltration
  4. Condensation Correct answer.

Explanation

Condensation is the change from water vapor to liquid water, forming cloud droplets around tiny particles. Evaporation is the reverse change, and infiltration and transpiration involve water on or in the ground and plants.

Question 46Earth and Space Science

Which human action would most increase the amount of water soaking into the ground rather than running off?

  1. Covering the yard with concrete
  2. Replacing pavement with gardens and soil Correct answer.
  3. Cutting down all trees on a slope
  4. Building a solid asphalt parking lot

Explanation

Soil and plant roots allow water to infiltrate, so replacing hard pavement with gardens increases groundwater recharge and reduces runoff. Hard surfaces and bare slopes do the opposite.

Question 47Earth and Space Science

A town pumps more water out of an underground aquifer than rainfall can replace. Which result is most likely?

  1. The groundwater becomes frozen
  2. Rainfall increases to refill the aquifer
  3. The aquifer fills faster because it is empty
  4. The water table drops and wells may run dry Correct answer.

Explanation

An aquifer is recharged slowly by water seeping down through soil and rock. If water is removed faster than recharge, the water table falls and wells must reach deeper or fail.

Question 48Earth and Space Science

Which natural process adds carbon dioxide to the atmosphere?

  1. Photosynthesis in green plants
  2. Rain washing dust out of the air
  3. Water freezing into ice
  4. Volcanic eruptions releasing gases Correct answer.

Explanation

Volcanoes release gases, including carbon dioxide, from Earth's interior into the atmosphere. Photosynthesis removes carbon dioxide, while the other choices do not add it.

Question 49Earth and Space Science

A city replaces its dark roofs with light-colored reflective roofs. Which effect on the local environment is most likely?

  1. More heat is absorbed, so the city gets hotter
  2. Less heat is absorbed, so surface temperatures are lower Correct answer.
  3. The ground beneath the city begins to melt
  4. Rainfall stops completely over the city

Explanation

Dark surfaces absorb more solar energy and release it as heat, which contributes to the urban heat island effect. Reflective light roofs bounce more sunlight back, lowering surface and air temperatures nearby.

Question 50Earth and Space Science

A community wants to reduce air pollution from burning fossil fuels. Which change would most directly help?

  1. Burning more coal to power homes
  2. Increasing the number of gasoline cars
  3. Clearing forests to build more roads
  4. Generating electricity from wind and sunlight Correct answer.

Explanation

Wind and solar power produce electricity without burning fuel, so they avoid the pollutants released by fossil fuels. The other choices increase emissions or remove vegetation that helps clean the air.