Introduction to Chemistry

Chemistry is the study of matter and the changes it undergoes.

Matter is defined as anything that has mass and takes up space.

Atoms are the fundamental building blocks of matter.

Each element is made of the same kind of atom. Oxygen is made of Oxygen atoms.

A compound is made of two or more different kinds of elements chemically bonded.

Total disorder, much empty space, particles have complete freedom of motion and are far apart.

Disorder, particles or clusters of particles are free to move relative to each other; particles close together.

Ordered arrangement; particles are essentially in fixed positions; particles close together.

A mixture with non-uniform composition, where different components are visible.

A mixture with uniform composition throughout; components are evenly distributed.

A homogeneous mixture with variable composition.

A substance with constant composition that cannot be separated into simpler substances by physical means.

A pure substance that cannot be separated into simpler substances by chemical means.

A pure substance made of two or more elements chemically combined.

Properties that can be observed without changing a substance into another substance (e.g., boiling point, density, mass, volume).

Properties observable when a substance is changed into another substance (e.g., flammability, corrosiveness, reactivity with acid).

Properties that are independent of the amount of substance (e.g., density, boiling point, color).

Properties that depend on the amount of substance present (e.g., mass, volume, energy).

Changes in matter that do not change the composition of a substance (e.g., changes of state, temperature, volume).

Changes that result in the formation of new substances (e.g., combustion, oxidation, decomposition).

A separation technique that utilizes differences in the boiling points of substances to separate a homogeneous mixture into its components.

A separation technique in which solid substances are separated from liquids and solutions.

A separation technique that separates substances on the basis of differences in solubility in a solvent.

A system of measurement based on seven base units, each representing a different physical quantity.

A system that converts base units into units that are appropriate for the item being measured.

The most commonly used metric units for volume (L) and the milliliter (mL).

By definition temperature is a measure of the average kinetic energy of the particles in a sample.

The Celsius scale is is based on the properties of water. 0°C is water freezing, 100°C is water boiling.

The SI unit of temperature and is based on the properties of gases. There are no negative Kelvin temperatures.

A scale not used in scientific measurements °F = 9/5(°C) + 32

A physical property of a substance and equals mass divided by volume.

Digits that were measured.

All nonzero digits are significant.

Zeroes between two significant figures are themselves significant.

Zeroes at the beginning of a number are never significant.

Zeroes at the end of a number are significant if a decimal point is written in the number.

When addition or subtraction is performed, answers are rounded to the least significant decimal place.

Answers are rounded to the number of digits that corresponds to the least number of significant figures in any of the numbers used in the calculation.

Refers to the proximity of a measurement to the true value of a quantity.

Refers to the proximity of several measurements to each other.