Praxis. Elementary Ed. Science 2026

Question 1

Praxis. Elementary Ed. Science 2026. Which of the following is the most abundant gas in Earth’s atmosphere?

• Hydrogen
• Nitrogen
• Helium Praxis. Elementary Ed. Science 2026
• Methane

Question 2

Which of the following best helps to explain why stars appear to revolve around Polaris, as viewed from the Northern Hemisphere?

• Earth and the rest of the solar system revolve around Polaris.
• All stars revolve around Polaris.
• Polaris is at the center of the universe.
• Earth rotates on its axis.

Question 3

Which THREE of the following characteristics are commonly used to describe the weather at a particular time and place?

• Average annual temperature
• Type of precipitation
• Wind speed
• Amount of cloudiness

Question 4

According to geologists, which of the following is true about most species that have lived on Earth?

• They are still living today.
• They existed during the Jurassic period.
• They have changed very little over time.
• They are extinct.

Question 5

Which of the following is a characteristic that distinguishes the giant outer planets in the solar system from Earth?

• They are made largely of hydrogen and helium.
• They are extremely dense.
• They lack orbiting moons. Praxis. Elementary Ed. Science 2026
• They tend to have a shorter period of revolution around the Sun.

Question 6

If a star located 15 light-years from Earth exploded into a supernova, the soonest an astronomer on Earth could observe the explosion is

• immediately
• in 15 seconds
• in 15 minutes
• in 15 years

Question 7

Of the following, which is the process by which rocks are broken down into smaller pieces through contact with air and water?

• Deposition
• Precipitation
• Sedimentation
• Weathering

Question 8

Water stored in aquifers is found in which of the following locations?

• Beneath Earth’s surface
• In rivers and lakes
• In ice caps and glaciers
• In the oceans

Question 9

A full Moon will be observed from Earth when the Moon is located in which of the following positions?

• 1
• 2
• 3
• 4

Question 10

Which of the following is most likely to cause the extinction of a warm-blooded carnivore?

• A small decrease in the average environmental temperature
• An increase in the number of herbivores the animal eats
• A significant alteration or destruction of the animal’s habitat
• An increase in the number of offspring the animal produces

Question 11

Most human cells have 46 chromosomes. How many chromosomes are in a human sperm or egg?

• 46
• 23
• 92
• 12

Question 12

Which of the following biomes is characterized by the presence of permafrost?

• Tropical rain forest
• Tundra
• Grassland
• Desert

Question 13

A virologist injects a mouse with a weakened version of a deadly virus. What has the virologist developed?

• A new species of virus
• A cure for the virus
• A vaccine for the deadly virus
• A mutation of the virus

Question 14

Which of the following are examples of structural adaptations?

• Some birds have long, curved beaks that they use to extract nectar from flowers
• Some birds have webbed feet that allow them to swim and dive efficiently in water
• Some birds migrate to warmer climates during the winter
• Some birds store extra food during the fall to survive the winter

Question 15

Which of the following organisms are characterized by bilateral symmetry, bony endoskeletons, and dependence on external heat sources to maintain body temperature?

• Mammals
• Birds
• Reptiles
• Amphibians

Question 16

What is the smallest unit of water that still retains the chemical properties of water?

• A proton
• An atom of oxygen
• A molecule
• A cloud droplet

Question 17

In a neutral atom, which two subatomic particles must be equal in number?

• Protons and neutrons
• Neutrons and electrons
• Protons and electrons
• Nucleus and protons

Question 18

Magma that has cooled and solidified on Earth’s surface is best described as which of the following?

• Igneous rock
• Sedimentary rock Praxis. Elementary Ed. Science 2026.
• Metamorphic rock
• Magma

Question 19

How long does it take the Earth to complete one revolution around the Sun? Praxis. Elementary Ed. Science 2026

• One day
• One month
• One year
• Ten years

Question 20

Which of the following processes depend directly on solar energy?

• The water cycle
• Photosynthesis
• Atmospheric circulation
• Seafloor spreading

Question 21

Which is the densest layer of the Earth?

• Crust
• Mantle
• Outer core
• Inner core

Question 22

Which of the following is an example of a structural adaptation?

• Some birds have long, curved beaks that they use to extract nectar from flowers
• Some birds have webbed feet that allow them to swim and dive efficiently in water
• Some birds migrate to warmer climates during the winter
• Some birds store extra food during the fall to survive the winter

Question 23

A virologist injects a mouse with a weakened version of a deadly virus. What has the virologist developed?

• A new species of virus
• A cure for the virus
• A vaccine for the deadly virus Praxis. Elementary Ed. Science 2026
• A mutation of the virus

Question 24

Which of the following organisms are characterized by bilateral symmetry, bony endoskeletons, and dependence on external heat sources to maintain body temperature?

• Mammals
• Birds
• Reptiles
• Amphibians

Question 25

What is the smallest unit of water that still retains the chemical properties of water?

• A proton
• An atom of oxygen
• A molecule
• A cloud droplet

Question 26

In a neutral atom, which two subatomic particles must be equal in number?

• Protons and neutrons
• Neutrons and electrons
• Protons and electrons
• Nucleus and protons

Question 27

Of the following organisms, which are characterized by bilateral symmetry, bony endoskeletons, and a dependence on external heat sources for regulating body temperature?

• Insects
• Sponges Praxis. Elementary Ed. Science 2026.
• Mammals
• Reptiles

Question 28

Which of the following is the smallest unit of water that retains the composition and chemical properties of the compound?

• A proton
• An atom
• An element
• A molecule

Question 29

Which of the following taxonomic levels is made up of the most closely related groups of organisms?

• Family
• Kingdom
• Class
• Phylum

Question 30

The selective breeding of plants and animals is called

• natural selection
• artificial selection
• stabilizing selection
• disruptive selection

Question 31

Of the following, which is a reactant in the process of photosynthesis that is acquired by plants from the atmosphere?

• ATP
• NADPH
• Oxygen
• Carbon dioxide

Question 32

Which of the following types of pathogen is responsible for the common cold?

• Bacterium
• Virus
• Fungus
• Protozoan

Question 33

Which of the following organisms are generally the first to colonize an existing community that has been devastated by fire?

• Grasses and shrubs
• Deciduous trees
• Cacti and other succulents
• Coniferous trees

Question 34

Doing which of the following to a sample of gas in a container would most likely make the gas molecules move faster?

• Condensing
• Cooling
• Freezing
• Heating

Question 35

Which of the following involves a chemical change?

• Crushing a can
• Boiling water
• Burning a sugar cube
• Breaking a bottle

Question 36

The surface gravity on Mars is less than the surface gravity on Earth. Based on the information presented, which of the following properties would be significantly different for a solid object when it is on the surface of Mars compared with when it is on the surface of Earth?

• Length
• Mass
• Volume
• Weight

Question 37

Which of the following is an example of an element?

• Sand
• Salt
• Sulfur
• Sawdust

Question 38

In an experiment, a student observes an object as it travels in one direction along a straight path. Which TWO of the following measurements does the student need to calculate the average speed of the object?

• The object’s mass
• The distance traveled
• The elapsed time
• The environmental temperature

Question 39

In its pure state, which of the following is normally a liquid at room temperature?

• Lead
• Neon
• Gold
• Mercury

Question 40

Which of the following units is most appropriate for expressing a quantity of thermal energy?

• Joules
• Kilograms
• Meters
• Ohms

Question 41

Which of the following is the smallest unit of water that retains the composition and chemical properties of the compound?

• A proton
• An atom
• An element
• A molecule

Questions 42

A neutral atom always contains an equal number of which of the following?

• Protons and electrons
• Protons and neutrons
• Neutrons and electrons
• Protons and alpha particles