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Understand the principles of balancing charges in chemical bonding. Learn how to achieve equilibrium by pairing ions with opposite charges. Practice balancing different compounds like magnesium chloride and lithium nitride. Enhance your counting skills by determining the number of atoms in various molecules.
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Lesson Bonding (Week 12)
Charges for Bonding • To bond, you must balance out the charges like we have been learning. • To balance out (-4) you must have a …….? • To balance out a (+2) you must have a ……?
Balancing Charges • Right…..to balance out a (-4), you must have a total of (+4)…… • And to balance out a (-2), you must have at least (+2).
Balancing Charges • So….if Oxygen is (-2)…...you must have a (+2) charge…… • But can you use more than one ion to get a (+2) charge… • Na + Na = 2 Na • (+1) + (+1) = (+2)
Guided Practice – Number 1 So if you had (Mg+2)…how many (Cl-1) would you need to balance it out…..?
Guided Practice – Number 1 So if you had (Mg+2)…how many (Cl-1) would you need to balance it out…..? Yes…….you need 2 of them…… MgCl2 (+2) + (-1) + (-1) = 0
Guided Practice – Number 2 • If you had a (N-3) how many (Li +1) would you need to balance it out? • (N-3) would need a total of (+3) to balance it out…….so how many (Li +1) does it take to make a (+3) ?
Guided Practice – Number 2 • (N-3) would need a total of (+3) to balance it out…….so how many (Li +1) does it take to make a (+3) ? • Li3N
How do you know which to list first…..? • Metals are listed first….then nonmetals… • So instead of NLi3 it is Li3N
Guided Practice – Number 3 • Which would it be… • BeO or OBe
Guided Practice – Number 3 • Which would it be… BeO or OBe Right………BeO since metals are listed first
Counting • Remember when you count atoms…it is good to fill in the bubbles until you get really good at counting…. • 4NaCl = NaCl + NaCl + NaCl + NaCl = 4 Sodium and 4 Chlorine • 3 Li3N = Li3N + Li3N + Li3N • = 9 Lithium and 3 Nitrogen
Guided Practice – Number 4 • 4CaCl2 • How many CaCl2 ? • How many Calcium atoms? • How many Chlorine atoms?
Guided Practice – Number 4 • 4CaCl2 • How many CaCl2 ? • 4 CaCl2 = CaCl2 + CaCl2 + CaCl2 + CaCl2 • How many Calcium atoms? 4 • How many Chlorine atoms? 8