Atomic Vocab

1. Atom- the smallest particle of an element, electrically neutral


2. Gold Foil Experiment - experiment conducted by Ernest
Rutherford- determined the nucleus is small, dense and positively charged and
the atom is mostly empty space


3. Rutherford Model- developed after the Gold Foil
experiment; model of the atom with a small, dense positive nucleus and is
mostly empty space


4. Proton- positive subatomic particle found in the nucleus


5. Neutron- subatomic particle found in the nucleus with no charge


6. Electron- subatomic particle with a negative charge found outside
the nucleus


7. Orbital- a region of an atom in which an electron of particular
energy is most likely to be located


8. Nucleus- the dense, positively charged central core of an atom
containing protons and neutrons


9. Valence Shell- the outermost shell of electrons
in an atom


10. Valence Electron- the electrons in the outermost
energy level


11. Atomic Number- equal to the number of protons;
gives the identity of the atom


12. (Average) Atomic Mass- the weighted average of all the
naturally occurring isotopes of an element


13. Atomic Mass Unit- the mass of a proton or neutron


14. Mass Number- the sum of protons and neutrons


15. Bohr Model- diagram showing the nucleus and all electrons organized
into their energy levels


16.  Lewis Structure- a diagram that depicts
valence electrons as dots and shared electrons as lines around the atomic
symbol


17. Isotope- atom of an element with a particular number of neutrons


18. Ground State- when all the electrons in an atom or ion are in the lowest
energy state


19. Excited State- when an electron in the ground
state absorbs energy and jumps to higher energy levels, leaving vacancies in
lower energy levels