Presentation is loading. Please wait.

Presentation is loading. Please wait.


Similar presentations

Presentation on theme: "ION QUIZ."— Presentation transcript:


2 Today you will need your periodic table/ion sheet and your packet Warmup (3 minutes)
What is a valence electron? Draw the Lewis dot structures of magnesium and fluorine. What does the term “neutral” mean (in terms of math and science)?

3 Is the red guy a cation or an anion?
Is the red guy a metal or a nonmetal? Chemistry puts the "cation" in education. What's a cation afraid of? A dogion!

4 Ion: An atom (or group of atoms) that has lost or gained e- to follow the Octet Rule and is now electrically charged Metal atoms lose e- to form positive ions called cations: K+ Ca 2+ NH4+ Nonmetal atoms gain e- to form negative ions called anions: Cl- S2- CO32- Superscript written to the upper right shows the charge If the charge is +1 or -1, you don’t have to include the “1” Called an “oxidation number” Mg2+ F-

5 Write the (reduction) equation showing how flourine becomes an ion
Ionization F + e-  F- Neutral but unstable fluorine atom, F Same # electrons as neon, but NOT an atom of neon! Write the (oxidation) equation showing how magnesium becomes an ion Mg  Mg2+ + 2e- Same # e- as…which element?

6 What patterns do you see? Are there any exceptions to these patterns?
1A metals: +1 ions 2A metals: +2 ions 7A nonmetals: -1 ions 6A nonmetals: -2 ions

7 Special ions (refer to handout)
Some transition metals lose different numbers of electrons when they become ions They can have different charges as a cation, and must be written with roman numerals representing their charge (exception: Al3+) Examples? Polyatomic ions: group of more than one atoms with a charge (+ or -) Example: Why do chemists like nitrates so much? They're cheaper than day rates.

8 Ionic Bonds Na+ Cl- Nonmetal atoms remove e- from metal atoms.
The two atoms become oppositely charged ions that attract each other, resulting in an ionic bond. An ionic compound forms. Cl- Read through EX 1 on “Writing and Naming Ionic Compounds” Handout that shows the crisscross method.

9 another example: iron(II)phosphate Fe2+ PO43- Fe2(PO4)3 NOOOOOOO!
EX 2: Write the formula for the ionic compound calcium oxide Step 1: Write each ion with the correct charge. Look at periodic table group or cheat sheet for help. Ca2+ O2- Step 2: “Criss-cross” number associated with each charge (do not include the + or -) Ca2O2 Step 3: Remove any subscripts of 1. Eliminate both subscripts if they are the same. Write the formula. CaO EX 3: Write the formula for the ionic compound aluminum carbonate Al3+ CO32- Al2CO33 ???? Al2(CO3)3 another example: iron(II)phosphate Fe2+ PO43- Fe2(PO4)3 NOOOOOOO! Fe3(PO4)2

10 PO43- Fe 2+ Fe 2+ PO43- Fe 2+ 6- 6+ Ionic compounds aren’t present as individual molecules, they exist as large crystals with many many of the same ions. The subscripts show the RATIOS of the two ions --- one formula unit of this compound has 3 iron(II)’s and 2 phosphates. Fe 2+ Fe 2+ Fe 2+ PO43- PO43- PO43- PO43- 3:2 is simplified from 6:4 or 30,000:20,000 Fe 2+ Fe 2+ Fe 2+

11 Name  Formula potassium nitride copper (I) bromide
potassium phosphide magnesium fluoride K3N CuBr K3P MgF2

12 Name these 2 compounds: CoS Figure out which ions form the compound because the ion charge could be important. Since S forms S2-, Co must be Co2+ b. Name the ions, cation first, then anion c. Change ending to –ide if it’s a pure element. cobalt (II)sulfide d. Transition metals always get a roman numeral to indicate their charge! Na2SO3 sodium sulfite Common mistakes: sodium(II)sulfite sodium(I)sulfite sodium sulfide/sulfate

13 Formula  Name Na2O CuS LiBr CuCl Sodium Oxide Copper (II) Sulfide
Lithium Bromide Copper (I) Chloride

14 Name  Formula Ammonium Phosphate Iron (II) Nitrate Sodium Sulfate
Silver Acetate (NH4)3PO4 Fe(NO3)2 Na2SO4 AgC2H3O2

15 Formula  Name Fe(OH)3 Mg(NO2)2 NiCO3 Cd(HCO3)2 Iron (III) Hydroxide
Magnesium Nitrite Nickel (II) Carbonate Cadmium (II) hydrogen carbonate or Cadmium (II) bicarbonate

16 Name  Formula Sodium Dichromate Tin (II) Chromate
Magnesium Permanganate lead (IV) bisulfate Na2Cr2O7 SnCrO4 Mg(MnO4)2 Pb(HSO4)4

17 Work on your packet! Make sure you have the Precipitation Lab with you next class!

Download ppt "ION QUIZ."

Similar presentations

Ads by Google