Unit 1 - Structure and Properties of Matter Flashcards
(82 cards)
Electromagnetic Radiation
a form of energy
Electromagnetic Spectrum
the range of wavelengths or frequencies over which electromagnetic radiation extends (radio -> gamma). The most energetic waves has the highest frequency
Wavelength (lambda)
the distance between two consecutive peaks or troughs, length go one cycle
Frequency (nu)
waves(cycles)/sec , how often something occurs
Planck’s Quantum Theory
atoms and molecules could emit or absorb energy only in discrete quantities
Quantum (the energy of a photon of light)
the smallest quantity of energy that can be emitted or absorbed in the form of electromagnetic radiation. Plural is quanta
Photons
particles of light
Heisenberg Uncertainty Principle
You can not know the position and momentum of an electron/particle at the same moment in time.
Orbital
wave function of an atom
Principal Quantum Number
energy level and size of orbital (n)
Angular Momentum Quantum Number
- shape/type of orbital - which sub shell the electron is found in (l = n-1) The higher the value of l, the greater is the energy of the subshell within an energy level.
Magnetic Quantum Number
spacial orientation/ where to find electron in (ml=2l+1)
Spin Quantum Number
orientation of spin of axis (ms) - +ve spin goes in first
Pauli Exclusion Principle
no two electrons in the same atom can have identical values for all four of their quantum numbers
Aufbau Principle
The aufbau principle states that in the ground state of an atom or ion, electrons fill atomic orbitals of the lowest available energy levels before occupying higher levels (e.g., 1s before 2s). In this way, the electrons of an atom or ion form the most stable electron configuration possible.
Orbital diagram
square diagrams showing the electrons and spin in orbitals of equal energy
Electron Configuration short cut
use name of last noble gas, then follow it with the orbitals
Hund’s Rule
the most stable electron arrangement for an atom is the one with the highest number of unpaired electrons with parallel spins (spinning optimally at this point)
Excited State
when an electron absorbs energy, it moves to a higher shell or subshell
Ground State
all of the electrons are in as low an energy level as it is possible for them to be
Exceptions to Configuration
The electronic configurations of several elements such as Cr, Cu, Ag, Pt and Au do not follow the general rule. In each one of these, the atom is more stable when the highest occupied s subshell has one electron instead of two, and the highest occupied d subshell has one more electron than it should have.
Atomic radius
increases down period, decreases down group (because of protons, ENC, and shielding)
Ionization Energy
the minimum energy required for removing an electron from the highest occupied subshell of an atom or an ion at its gaseous, ground state (decreases down and increases across because of protons, ENC, and shielding)
Electronegativity
the ability of an atom to attract electrons in a bond
