A series of steps followed to solve problems including collecting data, formulating a hypothesis, testing it, and stating the conclusions.

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

The exactness of a measurement.

The application of science for practical purposes.

A system of ideas that explains many related observations and is supported by a large body of evidence acquired through scientific investigation.

A factor that changes in an experiment in order to test a hypothesis.

The ratio of the mass of a substance to the volume of the substance.

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

Anything that has mass and takes up space.

A combination of two or more substances that are not chemically combined.

A substance that cannot be separated or broken down into simpler substances by chemical mean.

A group of atoms that are held together by chemical forces.

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

The amount of force exerted per unit area of a surface.

The total kinetic energy of a substance's atoms.

A nonsolid state of matter in which the atoms or molecules are free to move past each other.

The change of state from a gas to a liquid.

The capacity to do work.

A state of matter that consist of free-moving ions and electrons.

The SI unit of pressure.

The movement of matter due to differences in density that are caused by temperature variations.

The quantity of heat required to raise a unit mass of homogenous material 1K or 1 degree C in a specified way given constant pressure and volume.

The energy that is transferred as electromagnetic waves, such as visible light and infrared waves.

The transfer of energy as heat through a material.

Any movements of matter that results from differences in density; may be vertical, circular, or cyclical.

A subatomic particle that has a negative charge.

An atom that has the same number of protons as other atoms, but has a different number of neutrons.

The SI base unit used to measure the amount of something.

A subatomic particle that has a positive charge and that is located in the nucleus of an atom.

The sum of the numbers of protons and neutrons in the nucleus of an atom.

A subatomic particle that has no charge and that is located in the nucleus of an atom.

The number of protons in the nucleus of an atom.

An electron that is found in the outermost shell of an atom.

A region in an atom where there is a high probability of finding electrons.

A vertical column of elements in the periodic table.

An element or compound that conducts electric current better than an insulator does but not as well as a conductor does.

An atom that has gained or lost electrons, and has a positive or negative charge.

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

A horizontal row of elements in the periodic table.

One of the elements of group 18 of the periodic table.

The law that states that the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements.

The attractive force that holds atoms or ions together.

An ion made of two or more atoms.

A large molecule that is formed by more than five monomer, or small units.

The attractive force between oppositely charged ions.

A bond formed when atoms share one or more pairs of electrons.

A covalently bonded compound that contains carbon.

A bond formed by the attraction between positively charged metal ions and the electrons around them.

The arrangement of atoms in a substance.

Substance that undergoes change in a chemical reaction.

New substances formed as a result of a chemical reaction.

The energy stored in a chemical bond.

Substance that affects the rate of a chemical reaction without being used up in the reaction.

Number that appears before a formula in a chemical equation.

State in which the forward and reverse paths of a physical or chemical change take place at the same rate.

The rate at which reactants change into products over time.