140 likes | 237 Views
Ionic and Metallic Bonding. Chapter 7. Valence Electrons. The _______________in an atom Their arrangement determines the bonding __________and activities of an atom S-Block– they are the same as the group number Na= 1 valence electron P-Block– They are the group number- 10
E N D
Ionic and Metallic Bonding Chapter 7
Valence Electrons • The _______________in an atom • Their arrangement determines the bonding __________and activities of an atom • S-Block– they are the same as the group number Na= 1 valence electron • P-Block– They are the group number- 10 C= 4 valence electrons F= 7 valence electrons Iodine… 7 valence electrons
Electron Dot Notation: Instead of drawing the orbital diagram, which can be long & complex, there is an easier way to represent the atoms. _______________________:is an electron notation in which only the _______________are shown, and are represented by dots around the element’s symbol. Lots and lots of examples… Valence electrons Dot notation
Ions Ion:______________________________ Cation: atom that has a +ve charge (A+). i.e. missing an e- Anion: atom that has a –ve charge (X-). i.e. has an extra e- Do the Lewis structure for Cl, Cl-, Na, Na+
Polyatomic Ions • An ion that consist of____________, covalently bonded together and carrying a charge. • Common Examples… • OH- (Hydroxide) • NO3- (Nitrate) • SO42- (Sulfate) • PO43- (phosphate) (draw their Lewis structures)
Ionic Bonding Most of Earth’s rocks & minerals are made up of compounds held together by ionic bonds. ________________:consists of positive (cat) & negative (an) ions that are combined such that the # positives = # negatives. e.g. Na -> Na+ + e-&Cl + e- -> Cl- Na++Cl-->NaCl(#+’s = #-’s) e.g.2. Mg & Cl
Most ionic compounds exist as a ______________of alternating +’ve & -’ve ions (NaCldia) (Screen 3.9 Coulomb’s law, 3.10 NaCl, 3.10.SB KBr)
Ionic Compounds: Molecular arrangement _________________: is the simplest collection of atoms from which an ionic compounds formula can be established. Ionic compounds can be represented by Electron Dot diagrams. e.g. NaCl
Ionic Solid Structure • Ionic crystals combine in an orderly arrangement known as a _________________ • Crystalline solids at room temperature Rutile (crystal and model of lattice)
Ionic Solids: Characteristics -high melting/boiling pts -_______________ -when molten (or dissolved in H2O) they become good_________________________
Metallic Bonding: • Metals have few valence e-’s (1,2or3) which roam freely as a “sea of electrons” throughout the metal. They do not belong to any particular atom • The atoms themselves are arranged in a______________________________. • The bonding between the metal atoms & this sea of electrons is called_______________. • It is NOT bonding between different types of metal atoms.
Metal Solids Metals can only come together when they are in their molten state.A mixture of 2 or more metals called an alloy. Characteristics: • highly conductive: electrical & heat • ___________ • ___________ • ___________
Alloys ____________________: some of the host metal atoms are replaced by other similar sized metal atoms. E.g’s: Brass: Copper (~2/3) & Zinc (~1/3) Bronze: Copper (~80%) & Tin (~20%) Sterling Silver: Silver (93%) & Copper (7%) 24 Karat Gold: Gold (100%) 18 Karat Gold: Gold (18/24 = 75%) & Silver
_______________: some of the holes (interstices) between the metal atoms are filled with small atoms. Makes the metal harder, tougher and more durable… better for building E.g’s: Steel: Iron & Carbon (small %)