{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

chapt7yp - CHAPTER 7 The Structure o f A toms a nd Periodic...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
CHAPTER 7 The Structure of Atoms and Periodic Trends I. Electron Configurations & the Aufbau Principle II. Electron Configurations & the Periodic Table III. Atomic Properties & Periodic Trends I. Electron Configurations and the Aufbau Principle A. General 1. Electron configuration is how the electrons are distributed among the various atomic orbitals in an atom. 2. Orbital box diagrams use boxes to represent orbitals and arrows to represent electrons. H IT] 1 S1 1
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
B. Pauli Exclusion Principle 1. Pauli exclusion principle states that no two electrons in an atom can have the same four quantum numbers. 2. As there are only two possible values for m s (+Y2 or -Y2) an orbital can only accommodate a maximum of two electrons of opposite spin. subshell # orbitals max. # e - s (1=0) p (1=1) d (1=2) f (1=3) c. Building-Up Principle - Aufbau Principle 1. Electrons occupy orbitals of the lowest energy available and fill in the following order: 1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s < 4d < 5p < 6s 2
Background image of page 2
2. Electron configurations of the 'first fifteen elements: 1 H 1s 1 2 He 1s 2 3Li 1s 2 2s 1 4 Be 1s 2 2s 2 s8 1 S2 2s 2 2p1 6 C 1 S2 2s 2 2p2 7 N 1s 2 2s 2 2p3 80 1 S2 2s 2 2p4 gF 1 S2 2s 2 2 p s 10 Ne 1 S2 2s 2 2p 6 11 Na 1 S2 2s 2 2p 6 3s 1 12 Mg 1s 2 2s 2 2p 6 3s 2 13 AI 1 S2 2s 2 2p 6 3s 2 3p 1 14 Si 1s 2 2s 2 2p 6 3s 2 3p2 1S P 1s 2 2s 2 2p 6 3s 2 3p3 3. Abbreviated noble-gas core electron configurations:- 3 Li 1 S2 2s 1 or 80 1 S2 2s 2 2p4 or 12 M g 1 S2 2s 2 2p 6 3s 2 or 1S P 1 S2 2s 2 2p 6 3s 2 3p3 or 4. Hund's Rule: Electrons enter unoccupied orbitals first before pairing. 5. Orbital box diagran1s of selected elements: 3 Li 3
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
6. Diamagnetism and Paramagnetism:- The magnetic properties of a substance can reveal certain information about the arrangement of electrons in an atom. Paramagnetic:- a substance that is weakly attracted by a magnetic field. Diamagnetic:- a substance that is slightly repelled by a magnetic field. t t t ~ Paramagnetic Diamagnetic unpaired electrons all electrons paired LL_ 111111 2p 2p What is the electron configuration of K ?
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}