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Phys Sci-Chap 4 & 5
vocab words
Question | Answer |
---|---|
nucleus | dense, positively charged mass located in the center of an atom |
proton | positively charged subatomic particle that is found in the nucleus of an atom |
electron | negatively charged subatomic particle that is found in the space outside the nucleus of an atom |
neutron | neutral subatomic particle that is found in the nucleus of the atom |
atomic number | unique number for each element that equals the number of protons in an atom of that element |
mass number | the sum of the number of protons and neutrons in the nucleus of an atom |
isotopes | atoms of a given element that have different numbers of neutrons and different mass numbers |
energy levels | the possible energies that electrons in an atom can have |
electron cloud | a visual model of the most likely locations for the electrons in an atom |
orbital | a region of space around the nucleus where an electron is likely to be found |
electron configuration | the arrangement of electrons in the orbitals of an atom |
ground state | a state in which all the electrons in an atom have the lowest possible energies |
periodic table | an arrangement of elements in columns, based on a set of properties that repeat from row to row |
period | a row in a periodic table of elements |
group | a column of elements in a periodic table |
periodic law | the pattern of repeating properties displayed by elements in the periodic table |
atomic mass unit (amu) | one twelfth the mass of a carbon-12 atom |
metals | elements that are good conductors of heat and electric current |
transition metals | elements that form a bridge between elements on the left and right sides of the periodic table |
nonmetals | elements that are poor conductors of heat and electric currents |
metalloids | elements with properties that fall between those of metals and nonmetals |
valence electrons | an electron that is in the highest occupied energy level of an atom |
alkali metals | the elements in Group 1A of the periodic table, not including hydrogen |
alkaline earth metals | the elements in Group 2A of the periodic table |
halogens | the elements in Group 7A of the periodic table |
noble gases | the elements in Group 8A of the periodic table |