attractive force that holds together the atoms in a molecule. basic types are ionic, covalent and metallic
a pure substance made up of only one type of atom; it cannot be broken down into simpler substances
a pure substance that contains atoms of two or more different elements combined in a fixed ratio.
a pure substance made up of two or more atoms which are combined in a constant ratio and held together by chemical bonds. The substance may have two of the same type of atoms or two different types of atoms.
process in which some properties of a substance change, but the substance is still the same. Liquid water freezing to ice is one example.
a process in which existing bonds are broken and new bonds are formed, producing substances which are different from the starting materials.
the substance that you start with in a chemical reaction
the new substance that are formed in a chemical reaction
A representation of a chemical reaction that uses symbols to show the relationship between the reactants and the products
a solid that forms as a result of mixing two solutions
A combination of element symbols which shows how many and which type of elements are in a compound.
a substance that is added to a reaction to show the presence or amount of another material, or to show the progress of a reaction (an example is an acid-base indicator like litmus paper or phenlophthalein).
a substance that speeds up a chemical reaction, but is itself not permanently changed by the reaction.
chemical bond formed when two atoms share one or more electrons.
chemical bond formed when one atom gains and a second atom loses electrons.
a reaction in which one element takes the place of another element in a compound
a reaction where two reactants exchange places in ionic compounds
a reaction where the compound breaks down to form two or more simpler substances
a reaction in which two or more substances combine to form a new compound. Also called synthesis.
evidence of a chemical reaction
color change, energy change (temperature), a gas is produced (bubbling), a precipitate forms
a reaction that absorbs energy more energy than it releases (feels cold if touched)
A reaction that releases more energy than it absorbs (feels hot if touched)
regular sized numbers in front of a chemical formula that indicate how many copies of that material are present in a chemical equation
small numbers written after and to the lower right of atoms or polyatomic ions that indicate how many copies of that atom or ion are in the chemical formula
Reactions that only take place in the presence of light. These reactions are often synthesis or decomposition reactions and depend on specific wavelengths of light to occur. Examples are the formation of ozone or smog and the decomposition of chlorine in swimming pools.
A reaction in which an acid reacts with a base and forms water and a "salt"
Ionic compounds that form from the ions left behind when an acid neutralizes a base. HX (acid) + YOH (base) → H⁺ + X⁻ + Y⁺ + OH⁻ (ions in solution) → HOH (water) + XY (salt)
A molecule that releases Hydrogen Ions (H⁺) when dissolved in water. These substances taste sour, react with metals and carbonates to form Hydrogen gas (H₂), and turn litmus paper red.
A substance that releases Hydroxide Ions (OH⁻) when dissolved in water. These substances taste bitter, feel slippery or soapy, react with oils and grease, and turn litmus paper blue.
A chemical change in which an element or a compound reacts with oxygen, often producing energy in the form of heat and light. Reactions with hydrocarbons produce carbon dioxide and water.
2.4 x 10⁴
4.386 x 10⁷
3.05 x 10²
6.000032 x 10⁶
8.75 x 10⁵
7.1 x 10⁻⁶
4.39 x 10⁻⁷
9.0 x 10³
1.03 x 10⁸
5.11 x 10¹⁰
1.6 x 10¹
8.49 x 10⁻²
1.0 x 10⁻³
1.25 x 10⁻⁴
3.7 x 10⁻⁵
the small number at the top right of a number or variable
#.### x10^ The way scientists write very large or very small numbers
a number written in it's regular form, "normal"
using one or more of the senses to gather information (taste, touch, see, hear or smell)
An idea, intuition or understanding based on data
A testable If, Then, Because prediction
a factor in an experiment that can change, either intentionally (manipulated) or unintentionally (uncontrolled)
a standard against which other conditions can be compared in a scientific experiment
the act of conducting a controlled test or investigation
facts, figures, and other evidence gathered through observations
the careful examination of data looking for patterns or trends that have meaning
a summary of whether the results of the experiment support the hypothesis
an organized way to ask questions using carefully developed methods and procedures
how close a measured value is to the true or real value
how close a series of measurements are to one another
mutual relationship between two factors
an observed effect so large that it would rarely occur by chance
obtaining a number that tells the amount of something
to make a careful guess related to the number, amount, or size
A unifying explanation for a broad range of hypotheses and observations that have been supported by testing
An observation that happens every time under a certain set of conditions
The study of matter and energy and the interactions between the two through forces and motion.
The study of the properties of matter and how matter changes
Describes the closeness, or reproducibility, of a set of measurements taken under the same conditions.
A description of how close a measurement is to the true value of the quantity measured.
The digits on either side of the decimal point that seem reasonably certain to have been measured (not zeros that are place holders).
A mathematical method of writing numbers using powers of ten to express really large or small numbers.
A chemistry problem solving tool that includes identifying what you have, what you need, and conversion factors in order to express an answer in a desired unit.
The factor-label pair written above the line in dimensional analysis.
The factor-lbel pair writtenbelow the line in dimensional analysis.
The study of matter and how it changes.
Anything that has mass and takes up space.
Amount of matter in an object.
How much space an object takes up
Scientist that studies matter and how it changes
Describing the characteristics of something without using numbers
Describing something using measurements and numbers
an organized process for investigating the world around us
A "testable" If, then, because prediction in science
A condition or a characteristic of matter that is measured or controlled in an experiment.
a variable that is intentionally changed in an experiment (manipulated variable)
a variable that is measured in an experiment (response variable)
A widely accepted hypothesis that has been tested many times which "best explains" and predicts future activities
The application of science to help people improve their lives.
writing or displaying numbers in terms of a decimal number "a" between 1 and 10, multiplied by a power of 10 in the form "a" x 10ⁿ
A number that is written just above the writing line.
How close a measurement is to the correct or accepted value
how close a measurement is to other measurements of the same thing
a meaningful digit in a measured value.
a standard amount used for measuring
The SI unit for measuring length
The SI unit for measuring mass
The SI unit for measuring volume
The SI unit for measuring temperature
Degree Celsius (°C)
A unit for measuring temperature often used in metric measuring
The process of changing a measurement from one unit to another.
a ratio that shows two units that are equal two one another
a measurement unit created by multiplying or dividing other units
the mass of a sample matter divided by its volume
2008 NIST SI Units List
The National Institute of Standards and Technology http://physics.nist.gov/cuu/pdf/sp811.pdf page 7
a characteristic of a substance that can be observed without changing the substance.
the physical form of a substance; solid, liquid, gas, or plasma
A state of matter that has definite shape and volume.
a state of matter that has a definite volume but no definite shape.
The chemical changes involved when one or more substances react, forming one or more different substances.
A change in matter that produces one or more new substances.
A mixture in which all of the individual substances are evenly mixed throughout.
a state of matter that has no definite volume or shape.
A characteristic that describes how a substance changes into one or more different substances.
A single kind of matter that is pure; has fixed composition and definite chemical and physical properties.
two or more substances mixed together.
A mixture in which one or more substances are unevenly mixed throughout.
A homogeneous mixture of one or more solutes dissolved in a solvent; can be solid, liquid or gas.
A substance that is dissolved in a solvent to make the solution.
a solid solution containing metals.
solution in which the solvent is water.
the substance that a solute is dissolved in; usually the substance in a solution that is present in the greatest amount.
A change that affects the appearance but not the chemical makeup of a substance.
Ability to do work or to produce heat.
A subatomic particle that has a positive charge and that is found in the nucleus of an atom.
A subatomic particle that has no charge and that is found in the nucleus of an atom.
A negatively charged particle that is found outside the nucleus of an atom.
a certain amount of electricity. Is also a measure of the positive or negative state of an ion.
A region with protons and neutrons that is located at the center of an atom and contains most of the atom's mass.
An attraction between two atoms resulting from the sharing of or transfer of electrons.
A pure substance made of only one kind of atom.
Number of protons in an atom.
the smallest particle of an element having the chemical properties of the element.
A one or two letter representation of an element.
A chart of the elements organized by atomic number and electron arrangement that shows the repeating pattern of their properties.
Elements on the left side of the periodic table; often shiny solids that are good conductors of heat and electric current.
Elements on the upper right side of the periodic table that are generally gases or dull solids; poor conductors of heat and electricity.
Elements along the staircase of the periodic table that have some characteristics of both metals and nonmetals.
existing as single atoms or ions.
A molecule consisting of pairs of bonded atoms. (remember HI BrONClF)
existing as groups of three or more bonded atoms.
A number written slightly below and to the right of a chemical symbol that shows how many atoms of an element are in a compound.
A molecule made up of atoms of two or more different kind of elements joined by chemical bonds.
A group of symbols that represents the number and kind of atoms in a substance.
Mole (abbreviated Mol)
The SI unit used to measure the amount of a substance. Is equal to 6.02 X 10²³ particles of any substance.
number of "representative particles" in a mole, 6.02 X 10²³
Refers to the type of particle present in a substance: usually atoms, molecules, or formula units.
two or more atoms held together by covalent bonds
The lowest whole-number ratio of ions in an ionic compound
the mass in grams of 1 mol of a substance
gram atomic mass
the mass of one mole of an element, found as the "atomic mass" on the periodic table, expressed as grams per mole (g/mol)
gram formula mass
the sum of the mass of all the atoms in one mole of an ionic compound, expressed as grams per mole (g/mol)
gram molecular mass
The sum of the mass of all the atoms in one mole of a particular molecule, expressed as grams per mole (g/mol)
a formula showing the lowest whole number ratio of atoms in a compound