Chemistry 1027A/B Chapter Notes - Chapter 1.2: Electronegativity, Negative Number, Valence Electron
Document Summary
Group 1: alkali metals one valence electron (ns1) Group 2: alkaline earth metals two valence electrons (ns2) Group 13: trieles three valence electrons (ns2np1) Group 14: tetrels four valence electrons (ns2np2) Group 15: pnictogens five valence electrons (ns2np3) Group 16: chalcogens six valence electrons (ns2np4) Group 17: halogens seven valence electrons (ns2np5) Group 18: noble gases eight valence electrons (ns2np6) S and p block elements are called the main group elements. D and f block elements are called the transition elements. Effective nuclear charge (z*) force felt by any given electron. A higher z* indicates a stronger attraction between the outer electrons and the nucleus. Z* increases as you move left to right across a row. Atom size decreases as z* increases, therefore it decreases as you move left to right across a row. Atom size decreases as you move from the bottom to the top of a group. Bond length distance between the centers of two bonded atoms.