1.5 Atomic Spectroscopy Flashcards
(30 cards)
Main group number
Number of electrons in valence shell in one atom of that element
Period number
Number of occupied shells in one atom of that element
Periodic table blocks (s, p, d, f)
Identity of highest energy subshell
Maximum number of electrons each orbital can hold
2
Maximum number of electrons s-subshell can hold
2
Maximum number of electrons p-subshell can hold
6
Maximum number of electrons d-subshell can hold
10
Maximum number of electrons f-subshell can hold
14
Aufbau principle
Electrons fill subshells in order of increasing energy; low -> high.
Ions
Charged particles formed from gain/loss of electrons. Electrons added/removed from highest energy subshell (highest n-value) in an atom.
2 exceptions to electron subshell configuration
Chromium (Cr)
Copper (Cu)
Contain half-filled 4s subshell (4s1, not 4s2), allowing each orbital in 3d subshell to be half/completely filled, which is a more stable configuration for them.
Ground state
Lowest energy level; most stable, so electrons occur naturally in this state. Singular.
Excited state
Electrons promoted to higher energy levels through absorption of photons. Unstable and temporary. Numerous.
Photon
Discrete quantised amount of energy, supplied as light, heat, or electrical energy.
Octet rule
Tendency of atoms to prefer to have eight electrons in their valence shell.
Will share, gain, lose electrons to do so.
Noble gas configuration.
Electromagnetic emissions
Excited state is unstable, so electrons will return to lower energy levels by emitting energy equivalent to the transition, and so the photon’s energy, as electromagnetic radiation.
These emitted photons have specific frequencies and wavelengths related to their energies; so, emissions are characteristic of certain elements.
Transition metals forming ions
Transition metals (d-block) lose electrons from valence shell (highest quantum number).
Isoelectric
Same number of electrons.
Number and distribution of electrons in cation’s or anion’s outermost shells match the electron configuration of the nearest preceding noble gas (isoelectric with noble gas configuration).
Line emission spectrum
Black background with colourful lines
Line absorption spectrum
Colourful background with black lines
Purpose of atomic absorption spectroscopy (AAS)
Detection of metal ions in small quantities - that is, in the ppm and ppb range. Uses absorption of light to measure the concentration of metal in a mixture.
Metals forming ions
Tend to lose electrons from valence shell
Non-metals forming ions
Tend to gain electrons to fill valence shell
Hollow cathode lamp
Emits light at specific wavelengths of the target element for absorption measurement.
