Term | Definition |
Atom | a part of a particle considered to be irreducible constituent of a specified system. |
Element | A fundamental, essential or irreducible constituent of a composite entity. |
Nucleous | the center of an atom |
Electron Shell | a grouping of electrons surrounding the nucleus of an atom |
Proton | a stable, positively charged subatomic particle in the Baryon family |
Neutron | an electrically neutral subatomic particle in the Baryon family |
Electron | A stable subatomic particle which and has a negative charge |
Atomic Number | The number of protons in an atomic nucleous |
Atomic Mass | the mass of an isotope of an element in atomic mass units |
Valence Electron | an electron in the outer shell of an atom |
Nonmetals | any element that lacks the physical and chemical properties of a metal |
Metal | any electro positive element that usually has a shiny surface and good conductors of heat |
Metalloid | a nonmetallic element that has some of the chemical properties of a metal |
Group | a column in the periodic table in which elements are placed with the same properties |
Period | Horizontal rows in the periodic table that represents the number of electron shells in that row |
Transition Elements | elements whos atoms have an incomplete sub-shell |
Representative Elements | elements in the first two groups and the last six of the periodic table |
Ion | an atom or a group of atoms that has acquired a net electric charge by gaining or losing one or more electrons |
Isotope | one of two or more atoms having the same atomic number but a different mass number |
Law of Conservation of Mass | matter can't be made nor destroyed, it can only be changed physically |
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