atomic structure Flashcards
atomic mass
1/12 of the mass of the most abundant isotope of carbon
electromagnetic force
attracts opposite electrical charges
strong nuclear force
binds together protons and neutrons within the nucleus
weak nuclear force
responsible for radioactive beta decay- changing protons to neutrons and vice versa
gravitational force
brings objects together and creates curves in the fabric of space-time
A in nuclide notation
mass number
Z in nuclide notation
atomic number (number of protons)
isotopes
same number of protons but different number of neutrons
shell filling rule
2n2 electrons in each shell
Aufbau principle
atomic orbitals are filled with electrons starting at the lowest available energy states
pauli exclusion principle
no two electrons can have the same set of quantum numbers (cannot have the same energy levels)
hunds rule
electron shells requires single occupancy of an orbital by an electron before pairing
octet rule
the tendency for atoms to prefer to have 8 electrons in the outer shell
covalent bonding
non-metal atoms sharing a pair of electrons
ionic bonding
opposite charges attracting
band theory
metals have an energy band above the valence band called the conduction band which overlaps with the valence band so that there is no energy gap
excitation
- energy of the incident photon is equal to the energy gap
- all the energy of the incident photon is transferred as KE raises it to the next available orbital shell
- electron will fall back to its original orbital shell, emitting radiation in the process
ionisation
- energy of incident photon is greater than the energy gap
- all the energy of the incident photon is transferred to the electron as KE, causing the electron to be liberated and resulting in ionisation
- electron vacancy will be filled by an electron from another shell, emitting radiation in the process.
