Physical and Chemical Changes Flashcards
(26 cards)
What is a chemical change?
A process where substances combine or break apart to form new substances.
True or False: Physical changes result in the formation of new substances.
False
Which of the following is a sign of a chemical change? A) Color change B) Shape change C) Size change
A) Color change
Fill in the blank: A __________ change does not alter the chemical composition of a substance.
physical
What is an example of a physical change?
Melting ice into water.
What is the main difference between chemical and physical changes?
Chemical changes produce new substances; physical changes do not.
True or False: The boiling of water is a chemical change.
False
What happens during a chemical reaction?
Bonds between atoms are broken and formed to create new substances.
Which process is an example of a chemical change? A) Dissolving sugar B) Rusting iron C) Chopping wood
B) Rusting iron
Fill in the blank: During a __________ change, the form of a substance changes but its identity remains the same.
physical
What is a common indicator of a chemical change?
Production of gas, color change, or formation of a precipitate.
True or False: Freezing water is a physical change.
True
What is combustion?
A chemical change that occurs when a substance reacts with oxygen, producing heat and light.
What is the term for the new substances formed in a chemical reaction?
Products
Which of the following is a physical change? A) Baking a cake B) Dissolving salt in water C) Burning wood
B) Dissolving salt in water
Fill in the blank: In a __________ change, energy may be absorbed or released.
chemical
What is the law of conservation of mass?
Matter cannot be created or destroyed in a chemical reaction.
True or False: All physical changes are reversible.
False
What is a precipitate?
A solid that forms and settles out of a liquid mixture during a chemical reaction.
What is an example of a chemical change that occurs in everyday life?
Cooking food.
Which of the following is NOT a physical change? A) Cutting paper B) Melting wax C) Burning candle
C) Burning candle
Fill in the blank: A __________ change can often be observed by a change in temperature.
chemical
What does it mean for a reaction to be exothermic?
It releases energy in the form of heat.
True or False: All chemical changes are irreversible.
False
