ELECTROMAGNETIC SPECTRUM
ELECTROMAGNETIC SPECTRUM
OUTER (VALENCE) ELECTRONS AND ATOMIC
STRUCTURE• Outer Valence Electrons in Atoms &
Molecules Give Rise to Atomic and Molecular Spectra in U.V. and VISIBLEU.V. and VISIBLE Portions of the Electromagnetic Spectrum
ORBITALS
• Remember:– An Atomic Orbital is actually a Wave Functionwhich describes the probability of
finding an electron in a particular region of space around a central nucleus
ENERGY LEVELS FOR HYDROGEN ATOMIC
ORBITALS
ATOMIC QUANTUM NUMBERS
• Principal Quantum No: n = 1,2,3,1,2,3,…
• Angular Momentum Q. No: l = 0,1, … (n-1)
• Magnetic Q. No: ml = -l,…0,…,+l-l,…0,…,+l
• Spin Q. No: s = +/- ½+/- ½
ANGULAR QUANTUM NOS.
Angular Q. No: Letter
l = 0 sl = 1 pl = 2 dl = 3 f
ORBITALS vs. PRINCIPAL Q. No. n
• e.g. n = 4, l = 0,1,2,3
• So l = 0 4s l = 1 4p l = 2 4d l = 3 4f
• Ml values (–1 …+1). Adds up to (2l +1)
• So: One 4s orbitalThree 4 p orbitalsFive 4d orbitalsSeven 4f orbitals
HYDROGEN s ORBITALS
HYDROGEN 2px ORBITALS
HYDROGEN 2py ORBITALS
HYDROGEN 2pz ORBITALS
HYDROGEN 3d ORBITALS
Blackbody Radiation vs. Frequency
(Wavelength)