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the atom u3, l1&l2
Term | Definition |
---|---|
atom | is the smallest particle into which an element can be divided and still be the same element. |
electron | negatively charged particles. |
nucleus | a small, dense center that has a positive charge and is surrounded by moving electrons. |
proton | positively charged particles in the nucles |
neutron | nucleus contains uncharged particles |
electron cloud | electrons move within an area around the nucleus. |
atomic cloud | number of protons in the nucleus of an atom |
mass number | the total number of protons and neutrons in an atom's nucleus. |
periodic table | Mendeleev's arrangement of the elements |
chemical symbol | is an abbreviation for the element's name. |
average atomic mass | an atom is the weighted average of the mass of all the naturally occurring isotopes of that element. |
metal | are elements that are shiny and conduct heat and electricity well. |
nonmetal | are poor conductors of heat and electricity. |
metalliod | are elements that have some properties of metals and some properties of nonmetals. |
group | each vertical column of elements(from top to bottom) on the periodic table. |
period | each horizontal row of elements(from left to right) on the periodic table. |