P/C Changes

Which is an example of a physical change?

• apples cut into pieces for a fruit salad

• enzymes in your stomach breaking down a slice of pizza

• metal rusting

• sodium metal and chlorine gas combine to form sodium chloride

Is ice melting a physical or chemical change?

• physical, because it changes state

• physical, because it forms a new substance

• chemical, because it changes state

• chemical, because it forms a new substance

Which is a sign of a chemical change?

• a rotting potato giving off a bad smell

• a popsicle melting in the sun

• a block of cheese being cut into smaller pieces

• a glass breaking

Which is a physical change in digestion?

• teeth grinding crackers into smaller pieces

• enzymes in saliva breaking down the starches into crackers and converting them to sugars

• enzymes in the stomach breaking down food

• bacteria in intestines converting lactose into simple sugars

Photosynthesis and cellular respiration both _____________.

• involve a chemical change

• involve a physical change

• occur in plants and animals

• only occur in plants

In a chemical change, ____________.

• a new substance is formed

• mass can be created

• energy can be created

• the composition of the substance remains the same

The products of photosynthesis are _______________.

• sunlight, carbon dioxide, water

• water, glucose, oxygen

• sunlight, water, oxygen

• oxygen and glucose

The reactants of photosynthesis are _______________.

• sunlight, carbon dioxide, water

• water, glucose, oxygen

• sunlight, water, oxygen

• oxygen and glucose

Bobo wants to separate a mixture by boiling it. What kind of change is this?

• physical

• chemical

• impossible

• dangerous

_______________ chemically break down food in digestion.

• Enzymes

• Teeth

• Your stomach

• Intestines