Ionic Bonding and Compounds

Valance Electrons Electrons in the highest occupied energy level of an element’s atoms Group 1A – 1 ve 2A – 2 ve 3A – 3 ve 4A – 4 ve And so on Valence electrons are usually the only electrons used in chemical bonds

Electron Dot Structure Diagrams that show valence electrons as dots Example O

Electron Configuration for Cations Cations need to lose electrons to have a full valence electron level The Octet Rule: In forming compounds, atoms tend to achieve the electron configuration of a noble gas

Electron Configurations for Anions Anions need to gain electrons to have a full valence electron level The octet rule applies

Ionic Bonds Forces of attraction that binds oppositely charged ions Anions are attracted to cations By losing or gaining electrons, atoms will attain full valence electron shells

Ionic Compound Properties Most are crystalline solids Very stable structure High melting points Create electric current when melted or dissolved in water

Metallic Bonding The attraction of free-floating valence electrons to the positively charged metal ions Valence electrons are free to float from one part of the metal to another Good conductors of electricity Ductile and malleable

Metallic Structure Metals are crystalline Atoms are packed together tightly limiting the amount of space in between the atoms

Alloys Alloys are not “pure” metals Alloys may combine good qualities of two or more metals Substitutional alloys replace atoms with similar sized atoms Interstitial alloys involve small atoms that fit in between the other atoms