Ionic bond/covalent bond

上面位人兄......band theory用來講conductivity........你要講都唔該多d info ar.......講d唔講d
應該要用electronegativity來解釋......
簡單d咁講
ionic bond=其中一個donate electron,其中一個accept electron
convalent bond=share electron
如果大家的electronegativity都差不多/一樣,咁share electron is more preferred,因為大家爭electron的能力差不多
如果electronegativity其一個大,一個細,細的那一個就可以donate electron,咁就係ionic bond
好喇,咁metalloid呢?因為佢的electronegativity處於中間,同好多野比都唔差太大,所以就會form polar covalent bond之類的between ionic bond and covalent bond的東西 (即係又唔係好平均咁share,又唔係比晒)
ionic&covalent都係一d ideal的說法......
講多一樣野,metal & metal之間又點解唔form covalent bond而係metallic bond?因為.....metal的behavior同我地話的covalent compound唔同......所以.....又再分過.....呢個用返個band theory來解釋佢個behavior就差不多喇......

The world is not so simple. Your question can be answered by using band theory.
covalent bonds are formed between silicon, a metalloid, atoms, they form a covalent band, higher in energy is a conduction band. If the energy difference, called energy gap, between the covalent band and conduction band is not too large, it is 1.1 eV for silicon. Electrons can jump from covalent band to conduction band. Electrons in conduction band and holes in covalent band conducts current.