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Unit 3 Lessons 1+2
Matter and Energy
Term | Definition |
---|---|
atom | the smallest unit of an element that maintains the properties of that element |
electron | a subatomic particle that has a negative charge |
nucleus | in physical science, an atom's central region, which is made up of protons and nuetrons |
proton | a subatomic particle that has a positive charge and that is located in the nucleus of the atom |
neutron | a subatomic particle that has no charge and that is locate din the nucleus of an atom |
electron cloud | a region around the nucleus of an atom where electrons are likely to be found |
atomic number | the number of protons in the nucleus of an atom |
mass number | the sum of the numbers of protons and neutrons in the nucleus of an atom |
periodic table | an arrangement of the elements in order of their atomic numbers such that elements with similar properties fall in the same column, or group |
chemical symbol | a one, two, or three letter abbreviation of the name of an element |
average atomic mass | the weighted average of the masses of all naturally occurring isotopes of an element |
metal | an element that is shiny and that conducts heat and electricity well |
nonmetal | an element that conducts heat and electricity poorly |
group | a vertical column of elements in the periodic table |
period | in chemistry, a horizontal row of elements in the periodic table |