Glossary

Science-The knowledge gained by observing natural events and conditions in order to discover facts and formulate laws or principles.



Technology- The application of science for pracitcal purposes.



Scientific Law- A sumary of many experimental results and observations; a law that tellshow things work.



Scientific Theory- A series of steps followed to solve problems including collecting data,formulating a hypthesis, testing the hypothesis, and stating colnclusions.



Critcal Thinking- The ability and willingness to assess claims critically



Scientific Method- a series of steps followed to solve problems including colecting data, formulating a hypothesis, testing the hypothesis, and staing conclusions.



Variable-a factor that changes in an experiment in order to test a hypothesis



Length-a measure of the straight-line distance between two points



Mass- a measure of the amount of matter in an object



Volume-a measure of the size of a body or region in three-demsensional space



Weight- a measure of the gravitional force exerted on an object


Periodic Law- The law that states that the repeating chemical and physical properties of elements change periodically with the aomic numbersof the elements.


Period- In chemestry, a horizontal row of elements in the periodic table


Group- A vertical coloumn of elements in the periodic table (also called family); elements that share the same chemical properties


Ion- An atom, radical, or molecule that has gained or lost one or more electrons and has a negative or positvie charge


Atomic Number- The number of protons in thenucleus of an atom; the atomic number is the same for all atoms of an element


Mass Number- The sum of the protons and nuetrons in the nucleus of an atom


Isotope- An atom that has the same number of protons as other atoms of the same element do but that has a different number of nuetrons


Atomic Mass Unit (amu)- A unit of mass that describes the mass of an atom or molecule; it is exactly one-twelfth of the mass of a carbon atom with mass number 12


Average Atomic Mass- the weighted average of the masses of all naturally occuring isotopes of an element


Metal- An element that is shiny and that conducts heat and elecricity well


Nonmetal- an element that conducts heat andelecricity and that does not form positive ions in an electrolytic solution


Semiconductor- an element or compound that conducts electric current better than an insulator but not as well as a conductor


Alkali Metal- one of the elements of group of the periodic tabel (lithium, sodium, potassium, rubidium, cesium, and francium)


Alkaline-Earth Metal- one of the elements of group 2 in the peri0dic tabel (beryllium, magnesium, calcium, strontium, barium, and radium


Transition Metal- one of the metals that can use the inner shell before using the outer shell to bond


Halogen- one of the elements of group 17 of the periodic table (flourine, chlorine, brmine, iodine, and astaine); halogens combine with most metals to form salts


Nobel Gas- an un reactive element of group 18 of the periodic tabel (helium, neon, argon, krypton, xenon, or radon) the has eight electrons in its outer level (execpt for helium, which has two)