Electronic arrangement of the atom Flashcards
Niels Bohr
Proposed the idea of energy levels based of his study of emission spectra of excited hydrogen atoms in a discharge tube
(excited with a battery, beam isolated by slits, separated by prism, spectrum captured on screen)
energy level
fixed energy value of an electron in an atom
Continuous spectrum
contains many wavelengths or colors with no gaps
Bohr’s Theory
- Electrons orbit the nucleus along fixed paths called orbits or energy levels.
- Electrons in any one orbit have a fixed amount of energy. (quantized)
emission spectrum
spectrum created by the frequencies of light emitted by electrons in an excited state within atoms of an element
Flame tests
Sodium yellow
Potassium lilac
Copper blue-green
Barium green
Strontium red
Lithium crimson
Atomic absorption spectrum
spectrum obtained when light is passed through a gaseous sample of an element
Sub-level
subdivision of a main energy level and contains one or more orbitals of the same energy level
Heisenberg’s Uncertainty Principle
it is impossible to measure both the velocity and the position of an electron at the same time
Hund’s rule of Maximal Multiplicity
every orbital in a sublevel must be filled singly before doubly
Pauli exclusion principle
No more than two electrons can occupy an orbital and they must have opposite spin
Orbital
region near the nucleus in which there is a high probability of an electron being found
Atomic radius
Half the distance between the nuclei of two atoms of the same element joined by a single covalent bond
Electronic configurations
- 1s(2) 2s(2) 2p(6) 3s(2) 3p(6) 4s(2) 3d(10) 4p(6)
- in the case of copper and chromium 3d is filled before 4s as the filled/half-filled sublevels are more stable
