Honors Chemistry study guide: Unit 1 Matter

Matter
Anything that has mass and takes up space

Experiment
A set of controlled observations that test a hypothesis

Mass
A measure that reflects the amount of matter

Physical property
A characteristic of matter that can be observed or measured without changing the sample’s composition. Example: density, color, taste, hardness, and melting point

Liquid
A form of matter that flows, has constant volume, and takes the shape of its container.

Homogeneous mixture
One that has a uniform composition throughout and always has a single phase; also called a solution

Compound
A chemical combination of two or more different elements; can be broken down into simpler substances by chemical means and has properties different from those of its component elements

liter
The metric unit for volume equal to one cubic decimeter

Celsius
The metric unit of temperature measurement.

Experimental value
the value measured in the lab

Chemistry
The study of matter and the changes that it undergoes

Independent variable
In an experiment, the variable that the experimenter plans to change

Volume
the amount of 3-dimensional space occupied by an object

Chemical property
The ability or inability of a substance to combine with or change into one or more new substances

gas
A form of matter that flows to conform to the shape of its container, fills the container”s entire volume, and is easily compressed

Solution
A uniform mixture that can contain solids, liquids, or gases; also called a homogeneous mixture

Conservation of mass
the principle stating that matter is not created or destroyed during a chemical reaction

Error
The difference between an experimental value and an accepted value

Kilogram
The SI base unit for mass

Kelvin
The SI base unit of temperature

Scientific method
A systematic approach used in scientific study; an organized process used by scientists to do research and to verity the work of others

Dependent variable
In an experiment, the variable whose value depends on the independent variable

Extensive property
A physical property, such as mass, length, and volume, that is dependent upon the amount of substance present

Physical change
A type of change that alters the physical properties of a substance but does not change its composition

Vapor
Gaseous state of a substance that is a liquid r a solid at room temperature

Filtration
A technique that uses a porous barrier to separate a solid from a liquid

Accuracy
Refers to how close a measured value is to an accepted value

Percent error
The ration of an error to an accepted value

Gram
a metric unit of weight equal to one thousandth of a kilogram

Absolute zero
Zero on the kelvin scale which represents the lowest possible theoretical temperature; atoms are all in the lowest possible energy state

Observation
the act of making and recording a measurement

Theory
An explanation supported by many experiments; is still subject to new experimental data, can be modified, and is considered valid if it can be used to make predictions that are proven true

Intensive property
A physical property that remains the same no matter how much of a substance is present

Chemical change
A process involving one or more substances changing into new substances; also called a chemical reaction

Mixture
A physical blend of two or more pure substances in any proportion in which each substance retains its individual properties, can be separated by physical means

Distillation
A technique that can be used to physically separate most homogenous mixtures based on the differences in the boiling points of the substances

Precision
Refers to how close a series of measurements are to one another; precise measurements show little variation over a series of trials but might not be accurate

SI unit
International System of Units

Weight
A measure or an amount of matter and also the effect of Earth’s gravitational pull on that matter

Density
The amount of matt per unit volume; a physical property

Hypothesis
A tentative, testable statement or prediction about what has been observed

Scientific law
Describes a relationship in nature that is supported by many experiments

Pure substance
a sample of matter, either a single element or a single compound, that has definite chemical and physical properties

Solid
A form of matter that has its own definite shape and volume, is incompressible, and expands only slightly when heated.

Heterogeneous mixture
One that does not have a uniform composition and in which the individual substances remain distinct

Element
A pure substance that cannot be broken down into simpler substances by physical or chemical means

Accepted value
the correct value based on reliable references

Meter
The SI base unit for length

Temperature
A measure of the average kinetic energy of the particles in a sample of matter