CHEM 1000 Lecture 27: LEWIS THEROY

• School: York University
• Department: Chemistry
• Course: CHEM 1000
• Professor: Donald Hastie

Document Summary

Electrons, particularly valance electrons play role in chemical bonding. When elements combine to produce compounds, they attempt to achieve a full valence shell (8 e-) Electrons can be transferred from one atom to another to make ions. Way of representing valence electrons in element. Combo of lewis symbols represent sharing or transfer of e- (cid:449)e do(cid:374)"t usually see isolated io(cid:374)i(cid:272) (cid:272)o(cid:373)pou(cid:374)ds. (cid:374)o(cid:396)(cid:373)ally they"(cid:396)e isolated i(cid:374) (cid:272)(cid:396)ystals (cid:449)he(cid:396)e o(cid:374) a(cid:374)io(cid:374) (negative) is attracted to several cations (positives). Electrically neutrality means total number of each ion is same. Why? b/c energy cost of making ions is too high. Overall effects is that each atom has more valence electrons. Bond pairs- shared electrons; lone electrons- electrons are not shared. Bo(cid:374)ds do(cid:374)"t ha(cid:448)e to (cid:272)o(cid:373)e f(cid:396)o(cid:373) e(cid:395)ual sha(cid:396)i(cid:374)g of ele(cid:272)t(cid:396)o(cid:374)s. 1 bond pair- single bond, bond order=1. 2 bond pair- double bond, bond order=2. 3 bond pair- triple bond, bond order=3. Distance b/t 2 atoms joined b/t covalent bonds.