Question

a science teacher demonstrated physical and chemical changes by using a fork to hold a marshmallow over a lit candle. determine which of the following changes during this demonstration are chemical (c) or physical (p). the marshmallow changes shape the wick turns black the marshmallow burns the candle releases smoke the fork is hot the wax melts

Explanation:

Step1: Recall physical and chemical change definitions

Physical change - no new substances formed, change in state or shape. Chemical change - new substances formed.

Step2: Analyze "the marshmallow changes shape"

No new substances are formed, just a change in shape. So it's a physical change (P).

Step3: Analyze "the wick turns black"

Burning of wick forms new substances like carbon - black. So it's a chemical change (C).

Step4: Analyze "the marshmallow burns"

Burning of marshmallow forms new substances like carbon dioxide and water. So it's a chemical change (C).

Step5: Analyze "the candle releases smoke"

Burning of candle wax and wick produces smoke (new substances). So it's a chemical change (C).

Step6: Analyze "the fork is hot"

Heat transfer occurs, no new substances formed. So it's a physical change (P).

Step7: Analyze "the wax melts"

Change in state from solid to liquid, no new substances formed. So it's a physical change (P).

Answer:

the marshmallow changes shape: P
the wick turns black: C
the marshmallow burns: C
the candle releases smoke: C
the fork is hot: P
the wax melts: P