» Please take out your periodic table.
Ionic Compounds
Before we begin What are ions? How are they made? (Hint: Remember what happens to VALENCE electrons.)
(Put a line down the middle of the white board.) On one half draw a Bohr diagram for sodium. Make it stable (that is, make it into an ION.) What charge does it have? On the other half, draw a Bohr diagram for chloride. Make it stable (that is, make it into an ION.) What charge does it have?
Ionic Compounds Ionic compounds form when metals (+) combine with non-metals (-) to make a NEW ionic compound eg., sodium + chlorine > sodium chloride All ionic compounds have similar physical properties What are they? It s up to you to find out!!!
What are examples of physical properties?
Conductivity is a physical property. How do we test for conductivity?
Purpose - A. To test ionic compounds to find out the common properties Part B: (You will be given two Mystery Chemicals to determine if they are ionic or not!)
Ionic Compounds: are all white crystals are formed between metals and non-metals conduct electricity are malleable dissolve in water are all toxic have high melting points are fragile and can shatter are all crystals
Ionic Compounds:. are formed between metals and non-metals conduct electricity. dissolve in water. have high melting points are fragile and can shatter are all crystals
Examine the table below. Which compound is an example of an ionic compound? Explain how you know. A Description Melting Point Solubility Conductivity - white square crystals 186 o C Yes No B - white powder 175 o C No No C - yellow crystals 1176 o C Yes Yes
What are Ionic Compounds?
Remember Metals ions have a ( + ) charge = CATIONS Non metals ions have a ( - ) charge = ANIONS X X X X X Mg X X X X XX +2 X X X X X O X XX X -2 +2 Mg -2
Ionic Compounds - are made by the combination of a metal (positive ion) and a non- metal (negative ion). eg., sodium + chlorine > sodium chloride magnesium + oxygen -> magnesium oxide
General properties of Ionic Compounds are usually solids and form crystals. known as salts have High melting point are brittle and shatter under pressure When dissolved in water they conduct electricity
How do ionic compounds conduct electricity? Salt crystal has even patterns of the metal and non-metal in a crystal When dissolved, the ions separate in water
Let s Make Ionic Compounds!
Metal Non-Metal Formula Name magnesium oxygen MgO magnesium oxide calcium chlorine CaCl2 calcium chloride Lithium sulfur Li2S lithium sulfide Lithium nitrogen Li3N lithium nitride
Metal Non-Metal Formula Name calcium oxygen CaO calcium oxide Lithium sulfur Li2S lithium sulfide calcium nitrogen Ca3N2 calcium nitride magnesium oxygen Magnesium nitrogen MgO Mg3N2 magnesium oxide magnesium nitride
Forming Ionic Compounds (Using pencil & paper and getting the same answer!)
Lithium + Oxygen Li 1+ O 2- Li O 2 1 Li 2 O To make the formula follow three easy steps 1. Write the symbols for each element with the metal first. 2. Write the ionic charge above each symbol 3. Crisscross the numbers, drop the (+,-) signs and write the them as subscript
Magnesium and Nitrogen 2+ 3-3 2 1. Write the symbols for each element with the metal first. 2. Write the ionic charge above each symbol 3. Crisscross the numbers, drop the (+,-) signs and write the them as subscript
Naming Ionic Compounds 1. Name the metal first 2. Name the non metal second. Change the ending of its name to ide. Mg 3 N 2 Li 2 O Al Cl 3 Magnesium Nitride Lithium Oxide Aluminum Chloride
Chlorine and Aluminum Al 3+ Cl 1- Al Cl AlCl 3 1. Write the symbols for each element with the metal first. 2. Write the ionic charge above each symbol 1 3. Crisscross the numbers, drop the (+,-) signs and write the them as subscript 3
Calcium and Oxygen Ca 2+ 2 2 O 2- Ca O CaO The formula reduces to lowest terms whenever possible since the subscripts have a common factor 1. Write the symbols for each element with the metal first. 2. Write the ionic charge above each symbol 3. Crisscross the numbers, drop the (+,-) signs and write the them as subscript
potassium & sulfer potassium sulfide K2S
magnesium & oxygen magnesium oxide MgO
calcium & nitrogen calcium nitride Ca3N2
Classwork» Complete page 1 of the handout & keep in your notebook.
1. magnesium & oxygen 2. Lithium & sulfur 3. calcium & nitrogen