Unit 4 Review

Section 1: Forming Bonds1) 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

Lose 1 electron

gain 2 electrons

Gain 1 electron

Gain/ lose 4 electrons

none

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? __________Whichis 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

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.

Sodium cyanide _______________

Aluminum hydroxide ____________

Iron (III) oxide __________________

Titanium (I) sulfide ______________

Magnesium sulfide _____________

Strontium phosphide ____________

Lithium sulfide _________________

Rubidium phosphate ____________

NaCN

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 ____________________________

K2S _____________________________

CuO ____________________________

Ba3N2 ____________________________

FeN _____________________________

MgBr2 ___________________________

Fe3N2 ____________________________

calcium chloride

silver chloride

potassium sulfide

copper (II) oxide

barium nitride

iron (III) nitride

magnesium bromide

iron (II) nitride

NH4Cl ____________________________

AlPO4 ____________________________

LiNO2 ___________________________

Cs2SO3 __________________________

FeCl3 ____________________________

Cu2O____________________________

Ti2O _____________________________

Fe(NO2)2__________________________

ammonium chloride

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.

17. Describe the electron sea model of metallic bonding & draw a picture.

18. 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?

A mixture of metals

Example: steel = mix of iron and carbon

Delocalized electrons are free to move which is how electricity is transferred

Any Mixture of metals Ex: Steel- Mix of iron and carbon