Chemistry

the scientific study of the composition, structure, and properties of matter and the changes that matter undergoes

Chemical

substance that has a defined composition

Matter

Anything that has mass and takes up space

Atom

the smallest unit of an element that maintains the chemical properties of that element

Compound

A substance made up of atoms of two or more different elements joined by chemical bonds

Extensive property

A property that depends on the extent or size of a system

intensive property

A property that does not depend on the the amount of matter present, such as pressure temperature,or density

Mass

A measurement that reflects the amount of matter

Physical property

a characteristic of a substance that does not involve a chemical change, such as density, color, or hardness

Physical change

a change of matter from one form to another without a change in chemical properties

Change of static

the change of a substance from one physical state to another

liquid

the state of matter that has a definite volume but not a definite shape

Gas

a form of matter that does not have a definite volume or shape

Plasma

In physical science, a state of matter that's starts as a gas and then become ionized; it consists of free moving ions and electrons, it takes an electric charge, and it's properties differ from those of a solid, liquid, or gas

chemical property

a property of matter that describes a substance's ability to participate in chemical reactions

chemical change

A change that occurs when one or more substances change into entirely new substances with different properties.

Chemical reaction

the process by which one or more substances change to produce one or more different substances

reactant

a substance or molecule that participates in a chemical reaction

group

a vertical column of elements in the periodic table; elements in a group share chemical properties

family

a vertical column of elements in the periodic table

period

in chemistry, a horizontal row of elements in the periodic table

metal

an element that is shiny and that conducts heat and electricity well

nonmetal

an element that conducts heat and electricity poorly and that does not form positive ions in an electrolytic solution

metalloid

an element that has properties of both metals and not metals; sometimes referred to as a semiconductor

Scientific method

a series of steps followed to solve problems, including collecting data, formulating a hypothesis, testing the hypothesis and stating conclusion

system

a set of properties or interacting components considered to be a distinct physical entity for the purpose of study

hypothesis

an explanation that is based on prior scientific research or observations and that can be tested

theory

an explanation for some phenomenon that is based on observation, experimentation, and reasoning

quantity

something that has magnitude, size, or amount

SI

Le Système International d'Unités, or the International System of Units, which is the measurement system that is accepted worldwide

weight

A measure of the gravitational force exerted on an object; it's value can change with the location of the object in the universe

derived unit

a unit of measure that is a combination of other measurements

volume

A measure of the size of a body or region in three-dimensional space

density

the ratio of the mass of a substance to the volume of the substance of ten expressed as grams per cubic centimeter for solids and liquids as as grams per liter for gases

conversion factor

a ration that is derived from the equality of two different units and that can be used to convert from one unit to the other

dimensional analysis

a mathematical technique for studying dimensions of physical quantities

Accuracy

A description of how close a measurement is to the true value of the quantity measured.

Precision

the exactness of a measurement

percentage error

a figure that is calculated by subtracting the accepted value from the experimental value, dividing the difference by the accepted value, and then multiplying by 100

significant figures

a prescribed decimal place that determines the amount of rounding off to be done based on the precision of the measurement

Scientific notation

a method of expressing a quantity as a number multiplied by 10 to the appropriate power

directly proportional

the relationship between two variables whose ratio is a constant value

Inverse proportional

the relationship between two variables whose product is constant

Element

A substance that cannot be broken down into simpler substances by chemical means; all atoms of an element have the same atomic number

Solid

the state of matter in which the volume and shape of a substance are fixed