Physical and Chemical Changes (One)
Which of the following indicates a physical change rather than chemical?
A. Formation of rust
B. Dissolving sugar in water
C. Burning paper
B. Dissolving sugar
Which of the following is a physical change?
A. Burning paper
B. Crushing a rock
C. Rusting iron
B. Crushing a rock
What is the key difference between a physical and chemical change?
A. Physical changes create new substances
B. Chemical changes create new substances
C. Both create new substances
B. Chemical creates new substances
Which gas, when added to the atmosphere by cars and factories, contributes to climate change?
A. Carbon dioxide
B. Oxygen
C. Nitrogen
A. Carbon dioxide
How does the improper disposal of chemical waste affect the ecosystem?
A. It helps plants grow
B. It can poison soil and water
C. It creates new animals
B. Poisons soil and wat
Which combination best represents physical and chemical changes during cooking food?
A. Cutting vegetables (physical), caramelizing sugar (chemical)
B. Melting butter (chemical), boiling water (physical) C. Mixing salad (chemical), freezing juice (physical)
A. Cutting vegetables (physical), caramelizing sugar (chemical)
Why does dissolving sugar in water count as a physical change?
A. The sugar changes chemically
B. No new substance is formed
C. The sugar evaporates
B. No new substance formed
Which is NOT a typical sign of a chemical change?
A. Color change
B. Change in temperature
C. Change in shape
C. Change in shape
A factory releases hot water (a physical change) into a lake. What impact might this have on aquatic life?
A. None, water is still water
B. It cools the fish
C. It reduces oxygen levels, harming fish
C. Reduces oxygen levels
Why is the release of greenhouse gases considered a chemical impact on the atmosphere?
A. They cool the air
B. They trap heat and change climate
C. They are solid at room temperature
B. Trap heat and change climate
Which property change is NOT generally reversible?
A. Change in shape
B. Change in temperature
C. Change in chemical composition
C. Chemical composition
Which sign indicates a chemical change has likely occurred?
A. Change in shape
B. Release of gas or odor
C. Change in size
B. Release of gas or odor
Why can physical changes often be reversed, but chemical changes cannot?
A. Physical changes don’t create new substances
B. Chemical changes affect only shape
C. Physical changes always involve temperature changes
A. No new substances created
How can a change in matter’s state lead to a global environmental impact?
A. Releases frozen gases like methane
B. Freezes Earth’s core
C. Increases photosynthesis
A. Releases methane gas
Why does burning garbage (a chemical change) harm the environment?
A. It recycles materials
B. Releases toxic gases
C. Creates energy
B. Releases toxic gases
During a chemical reaction, which of the following stays conserved?
A. Mass
B. Color
C. Temperature
A. Mass
What happens to molecules during a chemical change?
A. They rearrange to form new substances
B. They only change state
C. They break apart completely
A. They rearrange
Why is boiling water NOT a chemical change?
A. It changes color
B. No new substance is formed
C. It gives off a gas
B. No new substance
What change of matter happens when oil spills spread in the ocean, and how does this affect marine life?
A. Oil freezes
B. Oil coats marine animals
B. Stays liquid, coats animals
Why can wildfires lead to more floods and landslides in the affected area after the fire is out?
A. Because the burned plants no longer hold soil in place
B. Because rainwater increases after a fire
C. Because animals build dams
Answer: A. Because the burned plants no longer hold soil in place
When iron rusts, which chemical elements combine to cause the change?
A. Iron and oxygen
B. Iron and hydrogen
C. Iron and nitrogen
A. Iron and oxygen
Vinegar is mixed with baking soda and bubbles form. What proves it's a chemical change?
A. Change in shape
B. Formation of a gas and new substances
C. Cooling
B. Formation of gas and new substances
A sugar cube is crushed and then heated until it caramelizes. Which part is chemical and which is physical?
A. Crushing = physical, caramelizing = chemical
B. Both are chemical
C. Both are physical
A. Crushing = physical, caramelizing = chemical
What state of matter is smoke from a wildfire mostly made of?
A. Solid particles and gases
B. Liquid droplets
C. Pure liquid water
A. Solid particles and gases
During a wildfire, trees undergo combustion. What two main types of matter are released into the air from this chemical reaction?
A. Oxygen and nitrogen
B. Carbon dioxide and water vapor
C. Hydrogen and Carbon dioxide
Answer: B. Carbon dioxide and water vapor