Physical Changes in Science Flashcards

Questions and Answers

What is a physical change?

In a physical change, one or more physical properties change, but it does not become a new substance.

List and explain two examples of a physical change.

Cutting a pizza in half and melting an ice cube.

What happens to mass during a physical change? Give an example.

Mass remains unchanged during a physical change, such as cutting a pizza.

Explain how mass was conserved in the conservation of mass lab.

The mass of the four nuts and bolts did not change during re-arrangement. Signup and view all the answers

Explain why an ice cube melting would be a physical change.

An ice cube melting is a physical change because it remains water. Signup and view all the answers

Explain why a piece of paper getting cut in half would be a physical change.

It is still paper; only the size changed. Signup and view all the answers

What is a chemical property?

A characteristic of matter observed as it changes to a different type of matter. Signup and view all the answers

What is a chemical change? Give an example.

A chemical change is when substances change into new substances with different properties, like a nail rusting. Signup and view all the answers

List four signs of a chemical change.

Formation of a precipitate, color change, change in temperature, production of bubbles. Signup and view all the answers

Compare and contrast physical and chemical changes.

Physical changes change a property of the substance, while chemical changes produce a new substance. Signup and view all the answers

Explain the concept of conservation of mass during a chemical change.

Mass remains the same before and after a chemical change. Signup and view all the answers

How does removing heat affect a chemical reaction? Give an example.

Removing heat slows down the chemical reaction, like storing food in a refrigerator. Signup and view all the answers

What is reactivity?

The ability of a substance to go through a chemical change. Signup and view all the answers

Study Notes

Physical Changes

A physical change involves a change in one or more physical properties without forming a new substance; the identity of matter remains the same.
Cutting a pizza in half or melting an ice cube are examples of physical changes.
When an ice cube melts, it transitions from solid to liquid, but remains water—a change of state, illustrating a physical change.
A piece of paper cut in half remains paper; only its size has changed.

Conservation of Mass

In a lab involving mass conservation, the total mass remains unchanged before and after a rearrangement of materials, indicating no mass is gained or lost.
Conservation of mass applies to both physical and chemical changes, ensuring mass is consistent throughout the process.

Chemical Properties and Changes

A chemical property describes characteristics that can be observed only during a change to a different substance, such as the ability to rust or burn.
A chemical change results in the formation of new substances with different physical and chemical properties; examples include a nail rusting or a reaction between baking soda and vinegar.

Signs of Chemical Changes

Key indicators of a chemical change include:
- Formation of a precipitate
- Color or odor change
- Temperature change
- Production of bubbles
- Energy change

Comparing Physical and Chemical Changes

Both types of changes involve alterations in matter, but physical changes do not create new substances, while chemical changes do.
Physical changes are reversible (e.g., freezing and melting), whereas chemical changes often produce irreversible transformations.

Heat and Chemical Reactions

Removing heat from a system generally slows down chemical reactions, as evidenced by food preservation techniques like refrigeration or freezing.

Reactivity

Reactivity refers to a substance's ability to undergo a chemical change, crucial for understanding how different materials interact during chemical processes.

Description

Explore the concept of physical changes in matter with these flashcards. Learn the definition, examples, and characteristics that distinguish physical changes from chemical changes. Perfect for students looking to enhance their understanding of basic science concepts.