Presentation on theme: "Ionic Compounds SNC2D. Review: Terms to Know ● Valence o The combining capacity of an element ● Valence shell o The outer electron shell of an atom, the."— Presentation transcript:
Review: Terms to Know ● Valence o The combining capacity of an element ● Valence shell o The outer electron shell of an atom, the electrons in this shell are called valence electrons ● Isoelectric with a noble gas o The same number of electrons as a noble gas
Review: Anions Cl — ● Easier to gain 1 electron than lose 7. ● Therefore the atom becomes an anion by gaining an electron. ● It becomes more stable by gaining an electron. It becomes iso- electric with Ar.
Review: Cations Na 1+ ● Easier to lose 1 electron than gain 7. ● Therefore the atom becomes a cation by losing an electron. ● It becomes more stable by losing an electron. It becomes iso-electric with Ne.
The Ionic Bond ● An ionic bond is when an electron from one atom is given to another atom and they are held together by strong electrostatic forces ● Ionic compounds are formed when ions form a compound
Formulas for Ionic Compounds ● Write symbols with the metal first (metal+nonmetal or cation+anion) ● Write the combining capacity for each element over the symbol ● Use “cross over” method and reduce numbers to lowest ratio Al S 3+2- 2 3 Mg S 2+ 2- 2 2 Mg S →
Naming Ionic Compounds ● Metal first (cation), non-metal second (anion) ● Change ending of anion to “ide” ● Examples: o magnesium + fluorine → magnesium fluoride o aluminum + sulphur → aluminum sulphide
Multivalent Ions ● Some metals form more than one type of ion o E.g. Fe can be Fe 2+ or Fe 3+ and we use roman numerals to tell them apart o iron (II) or iron (III) ● Review table 3 on page 198
Formulas for Multivalent Ions ● iron (II) + fluorine → iron (II) fluoride o Fe F → FeF 2 ● iron (III) + fluorine → iron (III) fluoride o Fe F → FeF 3 2+ 1- 3+ 1-