Chemical and Physical Changes Flashcards
a characteristic of a substance that can be observed directly or measured with a tool without changing the identity of the substance
Physical Property
a change in a substance that does not change the chemical makeup of the substance
Physical Change
a characteristic of a substance that cannot be observed without changing the identity of the substance
Chemical Property
a change that results in the formation of a new substance or substances
Chemical Change
a solid that forms during a chemical reaction that takes place in a solution
Precipitate
the forces that hold atoms together in molecules
Chemical Bond
process by which elements and compounds combine to form new substances
Chemical Reaction
Which indicates a chemical reaction is occurring
A. A substance melting
B. A substance evaporating
C. Bubbles forming when 2 substances are mixed
D. Temperature remaining the same when 2 substances are mixed
C. Bubbles forming when 2 substances are mixed
Which is the BEST evidence of a chemical change occurring when bread is baked?
A. The bread is warm and soft
B. Steam rises from the bread after it is baked
C. The dough rises during baking, and its texture changes
D. The bread appears exactly the same before and after baking
C. The dough rises during baking, and its texture changes
Which of these is NOT an example of a physical change of state?
A. Boiling
B. Stirring
C. Freezing
D. Evaporating
B. Stirring
Which is indicated if a gas forms when 2 or more substances are mixed?
A. Physical change
B. Chemical change
C. Physical property
D. Chemical property
B. Chemical change
Which BEST describes the solid that forms when 2 liquids combine in a chemical reaction?
A. Gas
B. Energy
C. Precipitate
C. Precipitate
Which task in the kitchen is a physical change?
A. Frying an egg
B. Baking a cake
C. Melting butter
D. Toasting bread
C. Melting butter
An ice cube is put into a heated pan. What will MOST LIKELY happen to the molecules in the ice as it is heated?
A. The molecules will begin to move slower
B. The molecules will begin to move faster
C. The molecules will begin to increase in density
D. The molecules will begin to condense in the air
B. The molecules will begin to move faster
Which is the BEST description for iron rusting quickly when exposed to water and salt?
A. A change of state
B. A chemical reaction
C. A physical reaction
B. A chemical reaction
Liquids placed in a beaker will settle in specific layers. Which physical property of matter does this illustrate?
A. Density
B. Polarity
C. Solubility
D. Malleability
A. Density
Which is a physical change?
A. A piece of wood burning
B. A copper roof changing color
C. Rust forming on an iron fence
D. A sheet of paper shredding
D. A sheet of paper shredding
Which is an example of a chemical reaction?
A. Vinegar added to baking soda forms a gas
B. Water evaporates into the air
C. Sugar dissolves in water
D. Corn kernels are crushed to form cornmeal
A. Vinegar added to baking soda forms a gas
Which of these could be a physical change?
A. Wood is burned in a fireplace
B. Cake batter is baked in an oven
C. A blue liquid and yellow liquid mix and make a green liquid
D. Baking soda is mixed with vinegar to make CO2
C. A blue liquid and yellow liquid mix and make a green liquid
Jay mixed 2 clear liquids and observes that they turn a cloudy white. Which MOST LIKELY happened?
A. Heat was given off
B. Rust was produced
C. The mass increased
D. A precipitate formed
D. A precipitate formed
Which is the BEST evidence that a chemical change has occurred?
A. Change of state
B. Release of energy
C. Temperature change
D. Formation of a new substance
D. Formation of a new substance
What part of digestion is mainly a chemical change?
A. Teeth break food into small pieces
B. Throat muscles push food toward the stomach
C. Stomach acids dissolve food into nutrients
D. Intestinal cells transport nutrients into the blood
C. Stomach acids dissolve food into nutrients
Which chemical change is MOST LIKELY to involve bubbling or an odor?
A. Color change
B. Gas production
C. Precipitate formation
D. Temperature decrease
B. Gas production
Which MOST LIKELY indicates a precipitate formed during a reaction?
A. The liquids changing colors
B. A solid appearing in the liquid
C. Gas bubbles appearing in the liquid
D. The temperature of the liquids changing
B. A solid appearing in the liquid
A chemical change happens when . . .?
A. Glass breaks into pieces
B. Dough bakes in an oven
C. Ice cream melts into a liquid
D. Electricity flows through a wire
B. Dough bakes in an oven
A potter knows that clay goes through a physical change whenever it becomes a bowl because the bowl . . .
A. Is a different color than the wet clay
B. Is the same substance as the wet clay
C. Has a different texture than the wet clay
D. Holds the same amount of water as the wet clay
B. Is the same substance as the wet clay
Which shows an example of a physical and chemical change?
A. Boiling water and melting wax
B. Rusting iron and baking a cake
C. Dissolving powder and shredding paper
D. Freezing water and burning coal
D. Freezing water and burning coal
