chem 1.1

What is chemistry?

The study of matter and how it changes

What is matter?

Anything that has mass and takes up space (volume)

What are chemical properties?

Properties describing how a substance interacts or reacts with other substances

What are physical properties?

Observable characteristics of a substance without it chemically changing

Describe a solid

Tightly packed; definite shape and volume

Describe a liquid

Less packed, can flow; definite volume, indefinite shape

Describe a gas

Loose, can flow; indefinite shape and volume

As energy (heat) is added, matter changes in what order?

Solid → Liquid → Gas

What is a pure substance?

A substance that cannot be physically separated further; classified as elements and compounds

What is a mixture?

Two or more substances combined without a chemical reaction; classified as homogeneous or heterogeneous

What is a heterogeneous mixture?

Not uniform, visibly distinguishable (ex: salad, sand + water, oil + water)

What is a homogeneous mixture?

Uniform, not visibly distinguishable; still physically separable (ex: salt water, air, steel)

What is a physical change?

Change in physical properties without altering chemical composition (ex: tearing paper, ice melting)

What is a chemical change?

Change in chemical identity; not reversible; a new substance forms (ex: burning, rusting)

evidence of a chemical reaction

Color change, Gas production , Light emission ,Temperature change, Precipitate formed.

What is filtration?

Using a physical barrier (filter) to separate substances based on particle size

What is evaporation?

Separating a dissolved solute from a solvent

What is distillation?

Separating two or more liquids based on different boiling points