Classifying Matter and Properties of Substances

These flashcards cover the classification of matter, properties of substances, the scientific method, and physical and chemical changes.

What defines an element?

Composed of one kind of atom; cannot be broken down by chemical reactions.

What is a compound?

Two or more different atoms chemically united in fixed proportions; can be broken down by chemical reactions.

How can mixtures be classified?

Classified as homogeneous (same composition) or heterogeneous (different composition).

What is a homogeneous mixture?

Has a consistent composition throughout (e.g., saltwater solutions).

Give an example of a heterogeneous mixture.

Oil and water, which do not mix uniformly.

What is the difference between physical and chemical properties?

Physical: observed without changing identity. Chemical: observed during a chemical change.

What is a physical change?

Affects physical properties without altering chemical composition.

What is a chemical change?

Forms new substances with different properties.

What does the Scientific Method involve?

Involves making observations, forming hypotheses, conducting experiments, and drawing conclusions.

What does the Law of Conservation of Mass state?

Matter is neither created nor destroyed; total mass of reactants equals total mass of products.

What characterizes solids?

Particles packed closely, fixed shape and volume.

What characterizes liquids?

Closely packed particles, definite volume, take container's shape.

What characterizes gases?

Particles move freely, fill container's shape, compressible.