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Periodic Table
Periodic table
| Term | Definition |
|---|---|
| periodic table | the arrangement of elements in order of their atomic numbers such that elements with similar properties fall into the same column or group. |
| chemical symbol | a one, two, or three letter abbreviation of the name of an element. |
| mass number | the weighted average of the masses of all the naturally occurring isotopes of an element. |
| metal | an element that is shiny and can conduct heat and electricity well. |
| non metal | an element that conducts heat and electricity poorly. |
| metalloids | an element that has properties of both metals and nonmetals. |
| group | a vertical column of elements in the periodic table which share chemical properties. |
| period | a horizontal row of elements in the periodic table. |
| atom | the basic unit of matter. |
| atomic number | the number of protons in the nucleus of an atom. |
| electron | a negatively charged particle that moves around the nucleus. |
| element | a pure substance that cannot be broken down into simpler substances by ordinary chemical means. |
| energy level | a particular region where electrons can orbit a nucleus. |
| isotope | one of several forms of the same element. |
| neutron | a particle with no charge located in the nucleus of an atom. |
| nucleus | the dense center of an atom containing protons and neutrons. |
| proton | a positively charged particle located in the nucleus of an atom. |