Physical and Chemical ChangePhysical and Chemical Change

Clues of a Chemical ChangeClues of a Chemical Change

A new colour appearsA new colour appears

eg. Oxygen Indicator eg. Oxygen Indicator SolutionSolution

Clues of a Chemical ChangeClues of a Chemical Change

Heat or light is given Heat or light is given offoff

A solid material (called a A solid material (called a precipitate) forms in precipitate) forms in liquidliquid

Clues of a Chemical ChangeClues of a Chemical Change

The change is The change is difficult to reversedifficult to reverse

Bubbles of gas are Bubbles of gas are formedformed

Situation

A piece of dry ice (solid carbon dioxide) is dropped into hot water. Large amounts of white vapour bubble out of the water.

Physical

Chemical

Explanation

The bubbles are carbon dioxide gas. There was no chemical change. Just a change in state.

Situation

Physical

Chemical

When George’s father makes wine from crabapples, bubbles form on the surface of the yeast and fruit mixture.

Explanation

A chemical change from apple juice to wine, it is no longer the same compound.

Situation

When margarine is left in a warm place for an extended period of time, it tastes sour.

Physical

Chemical

Explanation

The margarine is rotting, which is why it tastes sour.

Situation

Jane’s father opens up a new deodorant product. The room quickly smells like fresh flowers.

Physical

Chemical

Explanation

The deodorant is still deodorant, some particles have changed to vapour which we smell.

Situation

During a school volleyball game, Jennifer sprains her ankle. Her coach squeezes a bag at room temperature that quickly becomes very cold.

Physical

Chemical

Explanation

Inside the bag a chemical change has occurred which is endothermic.