Changes of State Chemical - changes among the states of matter

Change or Chemical Reaction- any change in which one or more substances are converted into different substances with different characteristic properties

Chemical Compound- a pure substance that can be decomposed into two or more simpler substances by a chemical change

Chemical Property- the ability of a substance to undergo a change that alters its identity

Chemistry- the study of the composition, structure, and properties of substances and the changes they undergo.

Element- a pure substance that cannot be decomposed by ordinary chemical change

Endothermic- process that absorbs heat

Energy- the ability to cause change or the ability to do work

Exothermic- process that releases heat

Extensive Physical Property- depends on the amount of matter present and includes mass, length, and volume

Gaseous State- the state of any matter that has neither a definite shape nor a definite volume

Groups or Families- vertical columns of elements in the Periodic Table; numbered consecutively from 1to 18

Heterogeneous Mixture- the composition and properties are not uniform- they differ from point to point in the mixture

Homogeneous Mixture- the composition and properties are uniform throughout the mixture

Hypothesis- a testable statement

Inertia- resistance to change in motion

Intensive Physical Property- don’t depend on the amount matter present and include melting point, boiling point, density, ductility, malleability, color, crystalline shape, and refractive index

Kinetic Energy- energy of an object in motion

Law of Conservation of Energy- Energy can be converted from one form to another, but it cannot be created or destroyed in ordinary chemical or physical changes.

Law of Conservation of Mass- Matter cannot be either created or destroyed in ordinary chemical or physical changes.

Law of Definite Composition- A chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound.

Law- a generalization that describes a wide variety of behaviors in nature

Liquid State- the state of any matter that has a definite volume and the ability to flow and take the shape of a container

Mass- a measure of the quantity of matter

Matter- anything that has mass and occupies space

Metal- an element that is a good conductor of heat and electricity

Metalloid- an element that has some properties characteristic of metals and others characteristic of nonmetals, and is a semi conductor

Mixture- a combination of two or more kinds of matter each of which retains its own composition and properties

Nonmetal- an element that is a poor conductor of heat and electricity

Period- horizontal rows of elements in the Periodic Table; numbered 1 to 7 from the top down

Phases- portions of matter that have both the same chemical properties and the same physical properties

Physical Change- any change in a property of matter that does not result in a change in identity

Physical Property- can be observed or measured without altering the identity of a material

Plasma- a gaseous system composed of positively-charged particles and negatively charged electrons

Precipitate- a solid that separates from a solution

Potential Energy- energy that an object has because of its composition

Products- the new substance or substances produced by a chemical reaction

Properties- characteristics that enable us to distinguish one kind of matter from another

Pure Substance- homogenous sample of matter that has the same composition and properties, whatever its source

Qualitative Information- non-numerical information

Quantitative Information- numerical information

Reactants- the substance or substances that undergo a chemical reaction

Scientific Method- a logical approach to the solution of problems that lend themselves to investigations by observing

Solid State- the state of any matter that has a definite shape and volume

Solution- Homogeneous mixtures

Theory- a broad generalization that explains a body of known facts or phenomena