Unit 4 Review

Section 1: Forming Bonds 1) Why are noble gases unreactive? 2) Why do ions form? 3) What is the octet rule? How is it used? 4) Which is more likely to form a compound – Mg or Ne? Why? 5) Why are the halogens and the alkali metals most likely to form ions? 6) How would the following elements achieve stability? Mg2+_________ O2-___________ C4+/-_________ Na+ __________ I1- __________ Xe _______ They have a full octet To achieve a stable octet (8 valence electrons) Atoms will gain/lose or share electrons to get 8 electrons. Used to predict ion formation. Mg, because it does not have 8 valence electrons. Because they only need one electron to be stable. Lose 2 electrons gain 2 electrons Gain/ lose 4 electrons Lose 1 electron Gain 1 electron none

9) What is the charge on anions? __________Which 7) As potential energy (energy to react) goes down, stability goes _____________. When atoms complete their valence shell they gain stability and lost their potential energy. These reactions are ____________________________________, meaning they give off energy. 8) What is the charge on cations? ________Which is more likely to form a cation – a metal or a nonmetal? Do cations form by gaining or losing electrons? Would they be smaller or larger than their neutral atom? _____________________________ 9) What is the charge on anions? __________Which is more likely to form a anion – a metal or a nonmetal? Do anions form by gaining or losing electrons? Would they be smaller or larger than their neutral atom? ______________________________ up exothermic “+” smaller “-” larger

11) Describe how an ionic bond forms between sodium and chlorine. 10) What is an ionic bond? 11) Describe how an ionic bond forms between sodium and chlorine. 12) Why don’t we talk about ionic compounds as individual molecules? 13) What is another name for ionic compounds? ___________________ 14) An ionic bond always forms between a __________________ & a _________________. 15) What are the properties of salts? Know what causes each property. 1. 2. 3. 4. Attraction between a cation and anion Sodium loses one electron to chlorine; Na+ + Cl- = NaCl Because we never have individuals – they repeat 1000’s of times in a crystal lattic salts Metal Nonmetal Hard and dense brittle High melting point Only conduct when dissolved.

NaCN Sodium cyanide _______________ Aluminum hydroxide ____________ Iron (III) oxide __________________ Titanium (I) sulfide ______________ Magnesium sulfide _____________ Strontium phosphide ____________ Lithium sulfide _________________ Rubidium phosphate ____________ Al (OH)3 Fe2O3 Ti2S MgS Sr3P2 Li2S Rb3PO4

Rubidium selenide _____________ Barium iodide _________________ Copper (II) hydroxide____________ Manganese (IV) chloride _________ Strontium acetate ______________ Calcium sulfate _________________ Mercury (I) nitride _______________ Cesium nitride _________________ Rb2Se BaI2 Cu(OH)2 MnCl4 Sr(C2H3O2)2 CaSO4 Hg3N Cs3N

CaCl2 ____________________________ AgCl ____________________________ calcium chloride CaCl2 ____________________________ AgCl ____________________________ K2S _____________________________ CuO ____________________________ Ba3N2 ____________________________ FeN _____________________________ MgBr2 ___________________________ Fe3N2 ____________________________ silver chloride potassium sulfide copper (II) oxide barium nitride iron (III) nitride magnesium bromide iron (II) nitride

ammonium chloride NH4Cl ____________________________ AlPO4 ____________________________ LiNO2 ___________________________ Cs2SO3 __________________________ FeCl3 ____________________________ Cu2O____________________________ Ti2O _____________________________ Fe(NO2)2__________________________ aluminum phosphate lithium nitrite cesium sulfite iron (III) chloride copper (I) oxide titanium (I) oxide iron (II) nitrite

Metals are not ionic but DO share many properties with ionic compounds. 16. Name one similarity and one difference between ionic and metallic bonding. Describe the electron sea model of metallic bonding & draw a picture. What physical properties does the electron sea model give metallic bonds? Similarity: attraction between positive and negative ions Difference: metals are malleable and ionics are brittle Positive metal cations have lost electrons to the “sea” Malleable and ductile Conductors Lustrous

19. What is an alloy? Give two examples. 20. What characteristic of metallic bonds enable them to conduct electricity? Any Mixture of metals Ex: Steel- Mix of iron and carbon Delocalized electrons are free to move which is how electricity is transferred A mixture of metals Example: steel = mix of iron and carbon