Which of the following is a chemical change? A. Ice melting, B. Water boiling, C. Iron rusting, D. Salt dissolving
C. Iron rusting
Which part of a plant cell is not found in animal cells?
A. Nucleus
B. Mitochondria
C. Cell wall
D. Cell membrane
C. Cell wall
Which layer of Earth is made mostly of solid iron and nickel?
A. Crust
B. Mantle
C. Outer core
D. Inner core
D. Inner core
Scientific Method:
What is the purpose of a control variable in an experiment?
A. To make results random
B. To change the outcome
C. To keep conditions consistent
D. To test multiple variables
C. To keep conditions consistent
A ball rolls faster down a steeper ramp. This happens because—
A. friction decreases
B. gravity increases
C. the force on the ball increases
D. the ball’s mass decreases
The force on the ball increases
Plants use sunlight to make food in a process called—
A. Respiration
B. Transpiration
C. Photosynthesis
D. Decomposition
C. Photosynthesis
Mountains can form when—
A. Two plates move apart
B. Two plates move toward each other
C. One plate slides under another
D. Plates stop moving
B. Two plates move toward each other
If an experiment is repeated several times with similar results, the data are—
A. Inaccurate
B. Reliable
C. Biased
D. Random
B. Reliable
When you rub your hands together, and they get warm, which energy transformation occurs?
A. Electrical → Thermal
B. Mechanical → Thermal
C. Chemical → Mechanical
D. Thermal → Mechanical
B. Mechanical → Thermal
In pea plants, tall (T) is dominant and short (t) is recessive. Which pair of alleles would make a short plant?
A. TT
B. Tt
C. tt
D. tT
C. tt
Which statement best describes climate?
A. It changes daily.
B. It describes long-term weather patterns.
C. It only occurs in deserts.
D. It is the same everywhere on Earth.
B. It describes long-term weather pattern
Why do scientists use models of atoms?
A. Atoms are too small to see
B. Models are more accurate
C. Models are easier to create
D. Atoms are not real
A. Atoms are too small to see
Sound travels fastest through—
A. air
B. water
C. steel
D. outer space
C. steel
Polar bears have thick fur and fat layers to help them—
A. Attract mates
B. Keep cool
C. Stay warm
D. Hide from prey
C. Stay warm
Which step in the water cycle involves water vapor changing into liquid?
A. Evaporation
B. Condensation
C. Precipitation
D. Runoff
B. Condensation
The first step in solving an engineering problem is to—
A. Build a prototype
B. Identify the problem
C. Test the design
D. Present the solution
"B. Identify the problem
What is formed when two or more different elements combine chemically?
A. Mixture
B. Solution
C. Compound
D. Molecule
C. Compound
In a food chain, the energy originally comes from—
A. The soil
B. The sun
C. The air
D. The water
B. The sun
What keeps the planets orbiting the Sun?
A. The Sun’s magnetic field
B. The pull of gravity
C. The planets’ own rotation
D. The Moon’s gravity
B. The pull of gravity
Which of these is an example of using technology to help the environment?
A. Burning more fossil fuels
B. Building solar panels
C. Cutting down forests
D. Using more plastic
B. Building solar panels