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Discover why the periodic table is shaped the way it is and how elements are arranged. Explore the concept of atomic and electron configuration, valence electrons, ionization energy, electron affinity, and common oxidation states.
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Why is the periodic table shaped like it is and how are the elements arranged?
Elements are arranged according to atomic # and e- configuration. Li: 3 e-’s 1s22s1 Na: 11 e-’s 1s2 2s2 2p63s1 K: 19 e-’s 1s2 2s2 2p6 3s2 3p64s1 Paramagnetic or diamagnetic?
Valence orbitals: outer shell orbitals beyond the closest noble-gas configuration Valence electrons: “the ones that can react” (located in the valence orbitals). The other e-’s are called core electrons and don’t react. 2s2 3s2 4s2 5s2 6s2 7s2 Elements in a vertical row have the same number of valence electrons.
Atomic size affects many properties, both physical and chemical Atomic sizes:
Smaller Smaller Li Be B C N O F Na WHY? K
Ionization Energy: The energy required to completely remove an e- from an atom in its gaseous state. Mg(g) Mg1+ + e- 1st ionization energy Mg1+(g) Mg2+ + e- 2nd ionization energy Question: Which of the above ionizations would have the highest ionization energy and why?
electron being lost: 1st 2nd 3rd 4th 5th 6th 7th
Increases Increases
Electron Affinites: The energy change that occurs when an electron is added to a gaseous atom . Cl(g) + e- Cl-(g) E = -349 kJ/mol What does the negative value mean?
The Halogen Family: Br2(l) Cl2(g) I2(s)
Alkali Metal Family Li K Na