AP Chem Chapter 1 Terms

Atoms

Tiny particles that are the building block of all ordinary matter

Molecules

An arrangement of atoms in a geometric sequence

Qualitative

Observations based on description

Quantitative

Observations based on measurements and numbers

Hypothesis

A tentative explanation for observations

Scientific Law

A breif statement that summarizes past observations and predicts future ones

Law of Conservation of Mass

Matter can not be created nor destroyed in a chemical or physical reaction

Scientific Theory

A model for the way nature behaves and why it behaves that way

Atomic Theory

All matter is composed of atoms

Matter

Anything that occupies space and has mass

Substance

A specific instance of matter

State

A substance’s physical form

Composition

The basic components of a substance

Crystalline

Atoms in a repeating order

Amorphus

Atoms have no pattern

Compressible

Atoms can be compressed closer together

Pure Substance

A substance made up of only one element

Mixture

Two or more substances together (not bonded)

Element

A substance that can not be chemically broken down any further

Compound

A substance composed of two or more elements

Heterogeneous

A mixture where the composition is not uniform

Homogenous

A uniform mixture

Decanting

Carefully pouring the liquid into another container

Distillation

A mixture is heated to evaporate a liquid

Volatile

Easily vaporizable

Filtration

Pouring a mixture into a filter paper to separate the solid and liquid

Physical Changes

Changes that alter only state or appearance, not composition

Chemical Changes

Changes that alter the composition of matter

Physical Property

A property that a substance displays visually without changing composition

Chemical Property

A property that a substance displays by changing composition

Energy

The ability to do work

Kinetic Energy

The energy associated with motion

Potential Energy

The energy associated with position and composition (energy while still)

Thermal Energy

A type of kinetic energy associated with the speed of molecules

Law of Conservation of Energy

Energy is neither created nor destroyed, but rather is converted or transferred

Mass

The measure of the quantity of matter within an object

Weight

The measure of the gravitational pull on an object

Derived Unit

A combination of units (m/s)

Volume

The measure of space taken up

Intensive Property

A property that’s not dependent on the amount of a substance

Extensive Property

A property that’s dependent on the amount of a substance

Signifigant Figures (Sig Figs)

The numbers in a measurement that are not just showing the decimal place and are not estimated

Accuracy

How close the measurement is to the actual value

Precision

How close a series of measurements are to each other

Random Error

Error that is equally likely to be too high or too low (no pattern)

Systematic Error

Error that is either too high or too low (pattern)

Dimensional Analysis

Using units as a guide to solve problems

Conversion Factor

A factional quantity with the units we’re converting to on top and the units we’re converting from on bottome

Conceptual Plan

The flow of unites throughout the problem