Physical and Chemical Changes

Front

Banana color: yellow

Back

intensive physical property

Answer explanation

The color of a banana, being yellow, is an intensive physical property. Intensive properties do not depend on the amount of substance, while extensive properties do. Therefore, the correct choice is 'intensive physical property'.

Front

Chopping firewood is a physical change because it alters the size, shape, and form of the wood without changing its chemical composition.

Back

All of the above.

Answer explanation

Chopping firewood is a physical change because it alters the size and shape of the wood, changes its form, and does not affect its chemical composition. Therefore, all the provided statements are correct.

Front

Chocolate color: brown.

Back

intensive physical property

Answer explanation

The chocolate's color, brown, is an intensive physical property because it does not depend on the amount of chocolate present. Extensive properties, like mass or volume, vary with the quantity.

Front

Chocolate bar length: 3 cm.

Back

Extensive property

Answer explanation

The length of the chocolate bar, 3 cm, is an extensive property because it depends on the amount of material present. Intensive properties, like density, do not change with the size or amount of substance.

Front

Burning is a...

Back

Chemical Change

Answer explanation

Burning is a chemical change because it involves a reaction that transforms substances into new products, releasing energy in the form of heat and light, unlike physical changes that do not alter the chemical composition.

Front

Rusting is a physical change?

Back

False

Answer explanation

Rusting is a chemical change, not a physical one, as it involves the reaction of iron with oxygen and moisture to form iron oxide. Therefore, the statement that rusting is a physical change is false.

Front

Rusting indicates a chemical change due to color change.

Back

Change in color of the object.

Answer explanation

Rusting involves a change in color, typically from metallic to reddish-brown due to iron oxide formation. This indicates a chemical change, as the original material's properties and composition are altered.

Front

NOT a physical property of a log?

Back

A log can be digested by a beaver.

Answer explanation

The correct choice is 'A log can be digested by a beaver' because this describes a biological interaction, not a physical property. The other options describe physical characteristics or uses of a log.

Front

Not a chemical property of a log:

Back

A log can be made into a stool

Answer explanation

The statement 'A log can be made into a stool' describes a physical use of the log, not a chemical property. In contrast, being flammable, rotting, and being made into paper involve chemical changes.

Front

Not a physical change: water reacts with sodium

Back

water reacts with sodium

Answer explanation

The correct choice is 'water reacts with sodium' because this is a chemical change, not a physical change. The other options involve changes in state or form of water, which are physical changes.