Which of these are physical changes in matter? Check all that apply boiling water a pencil being sharpened exploding dynamite fr

Answer: Boiling water, sharpening a pencil, freezing water.

Explanation: A physical change occurs without the rearrangement of atoms, leading to a change in size or shape of the material.

A chemical change involves the rearrangement of atoms, resulting in the creation of new substances.

Boiling water merely alters its state from liquid to gas and is thus a physical change.

Sharpening a pencil only reduces its size, qualifying as a physical change.

In contrast, the explosion of dynamite results in the formation of new substances, categorizing it as a chemical change.

Freezing water transforms its state from liquid to solid and is likewise a physical change.

Decaying cheese leads to new substances forming, hence it is a chemical change.

Explanation:

A physical change refers to a modification that does not alter the chemical makeup of a substance.

For instance, characteristics such as shape, size, mass, volume, density, and boiling point are considered physical properties.

Conversely, alterations that result in a change in the chemical structure of a substance are classified as chemical changes.

Examples include combustible substances like dynamite or decomposing cheese, which represent chemical transformations.

Thus, we can conclude that the following are all physical changes in matter:

• boiling water.

• a pencil being sharpened.

• freezing water.