| A | B |
|---|
| ORBITAL | A region in an atom where there is a high probability of finding electrons |
| FAMILY | vertical column on periodic table, also known as a group; elements have similar chemical and physical properties and same number of valance electrons |
| PERIOD | horizontal row of elements; elements in the same row have same number of orbitals |
| MAIN GROUP ELEMENTS | elements that do not include transition or rare earth metals |
| FAMILY | vertical column on periodic table, also known as a group; elements have similar chemical and physical properties and same number of valance electrons |
| PERIOD | horizontal row of elements; elements in the same row have same number of orbitals |
| FAMILY | vertical column on periodic table, also known as a group; elements have similar chemical and physical properties and same number of valance electrons |
| PERIOD | horizontal row of elements; elements in the same row have same number of orbitals |
| nonmetal | An element is dull, brittle, a poor conductor, and it does not react with hydrochloric acid. This element is most likely a _____. |
| Periodic Law | Statement that when the elements are arranged by increasing atomic number, there is a periodic repetition of their chemical and physical properties |
| PROTONS | POSITIVE ATOMIC PARTICLE FOUND IN THE NUCLEUS |
| NEUTRONS | NEUTRALLY CHARGED PARTICLE FOUND IN THE NUCLEUS |
| ELECTRONS | NEGATIVE ATOMIC PARTICLES FOUND SURROUNDING THE NUCLEUS |
| NUCLEUS | center of an atom; made up of protons and neutrons |
| PERIODIC LAW | properties of elements tend to repeat in a regular pattern when elements are arranged in order of increasing atomic number |
| FAMILY | vertical column on periodic table, also known as a group; elements have similar chemical and physical properties and same number of valance electrons |
| PERIOD | horizontal row of elements; elements in the same row have same number of orbitals |
| METALS | grouped on left side of periodic table; elements are shiny and conduct heat and electricity |
| NONMETALS | elements that are poor conductors of heat and electricity; grouped on the right side of periodic table |
| METALLOIDS | elements that have properties of metals and nonmetals |
| ATOMIC MASS | weighted average mass of element's isotopes |
| ISOTOPE | variation of an element that has the same number of protons but different number of neutrons |
| MENDELEEV | father of periodic table: determined the relationship of elements to organize them into a table |
| MOSLEY | determined the atomic number NOT atomic weight determined order of elements in the periodic table |
| MALLEABLE | can be hammered into thin sheets |
| DUCTILE | can be drawn into thin wires |
