Term | Definition |
electromagnetic radiation | radiant energy exhibits wavelike behavior and travels through space at the speed of light |
wave model | light consists of electromagnetic radiation traveling through space |
wavelength | the distance between two consecutive wave peaks/crests or troughs in a wave |
λ | wavelength |
frequency | the number of waves (cycles) per second that pass given point in space |
v | frequency |
speed | how fast a given peak travels |
amplitude | the displacement of a wave from zero; the height of a peak or the depth of a trough |
wave-particle nature of light | light consists of both waves and particles of energy |
photon | particle of electromagnetic radiation, packet of energy |
excited state | a higher energy state of an atom due to excess energy |
ground state | the lowest possible energy state of an atom |
emission spectra | bright line spectra produced when electrons drop to lower energy levels |
absorption spectra | dark lines on a rainbow background, electrons in cooler outer laters go up to higher energy levels and absorb proper frequencies |
Heisenberg Uncertainty Principle | it is impossible to know simultaneously both the exact momentum of an electron and its exact position in space |
atomic orbital | the three dimensional region in which there is a high probability of finding as electron in an atom |
principal energy level/principal quantum number | number denoted by n and which indirectly describes the size of the electron orbital |
sublevels | types of orbitals |
Aufbau Principle | electrons occupy atomic orbitals starting with the lowest energy orbital first |
Paul Exclusion Principle | an atomic orbitals can hold a maximum of two electrons and those two electrons must have opposite spins |
electron configuration | the arrangement of electrons in an atom |
orbital diagram | orbitals are subdivided into boxes or lines with arrows representing electrons |
Hund's Rule | when electrons occupy orbitals of equal energy, each is singly occupied before doubly occupied and all electrons in singly occupied orbitals have the same (parallel) spin |
valence electrons | the electrons in the outermost (highest) principal energy level of an atom; the electrons involved in bonding |
core electrons | inner electrons; the electrons that are not involved in binding atoms together |
atomic radius | measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding cloud of electrons |
ionization energy | the amount of energy required to remove an electron from an element |
n | number of sub levels |
letter | type/shape of orbital |
s | 1 |
p | 3 |
d | 5 |
f | 7 |
Layman | UV |
Balmer | visible |
Pashcen | IR |
increasing wavelength | as you go right |
increasing frequency | as you go left |
Rutherford | discovered nuclear atom and electrons; thought electrons revolved around around the nucleus like planets around the sun; not right cause electrons would collapse |
Bohr | still thought electrons revolved like planets (in orbits); the theorized that electrons could move up in discrete amounts of energy to larger orbits; problem - not specific orbits |
Schrodinger and de Broglie | developed wave-mechanical model; theorizes electrons have wave and particle properties; electrons move to different orbitals (not orbits) when energy is added; current model |
metals | lustrous appearance, malleable and ductile, excellent conductors of heat and electricity; tend to lose electrons to form positive ions |
nonmetals | lack properties of metals, some exceptions; tend to gain electrons to form negative ions |
metalloids | have properties of metals and nonmetals; along stair step |
reactivity (metals) | increases down a group, most likely to lose an electron; most reactive is francium |
reactivity (nonmetals) | decreases down group; doesn't desire another energy level filled as much as previous levels; most reactive is fluorine |