AP chem chapter 1+2 vocab

Qualitative observation

A description that does not involve numbers.

Measurement

Quantitative observations.

Filtration

A method of separating mixtures using a mesh to separate solids from liquids.

Pure substance

A substance with constant composition.

Distillation

A method of separating mixtures using the differences in volatility of the components.

Matter

Anything with the properties of mass, volume and inertia.

Experiment

A carefully controlled set of observations used to test a hypothesis.

Mixture

A material of variable composition that contains two or more substances.

Quantitative observation

A description that involves numbers and units.

Volatility

How readily a substance becomes a gas or vapor.

Chemical change

A change in which a substance becomes a new substance or substances with different properties and composition.

Science

The search for relationships that explain and predict natural phenomena.

Observation

Something that can be witnessed and recorded, using our senses (with or without tools) and measurements.

Element

Substances that cannot be decomposed into simpler substances by chemical or physical means.

Physical change

A change in the form of a substance, but not its chemical composition.

Scientific method

The process used to discover new facts or solve problems about natural phenomena.

Theory

A set of tested hypotheses put forth to explain why an observed behavior in nature happens.

Homogeneous material

A material having parts that are visibly indistinguishable.

Solution

A homogeneous mixture.

Heterogeneous material

A material having parts that are visibly distinguishable.

Scientific law

A statement that summarizes observed (measurable) behavior in nature.

Compound

A substance with constant composition that can be broken down into elements by chemical means.

Chromatography

A method of separating mixtures using the difference in affinity for a fixed phase and a mobile phase.

Hypothesis

One or more assumptions put forth to explain the observed behavior of nature.

Precision

Degree of agreement among several measurements of the same quantity.

Dimensional analysis

Using units of measurement as algebraic factors.

Weight

The force of gravity that acts upon a mass.

Measurement

A quantitative observation.

Significant figures

The digits in a measurement known with certainty, and the first uncertain digit.

Density

Mass per unit volume.

Mass

The amount of matter in an object.

Unit conversion factor

A ratio that converts a quantity in one unit into an equivalent quantity in a different unit.

Random error

An error that has an equal probability of being high or low.

Accuracy

An agreement of a particular value with a true or accepted value.

Systematic error

An error that always occurs in the same direction, high or low.

Extensive

Depends on amount of matter present

Intensive

Independent on matter present