electromagnetic spectrum. outer (valence) electrons and atomic structure u.v. and visibleouter...

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)