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Ions and Ionic Compounds. Admit Slip. What ions would Na and O create? If you put Na and O’s ions together, would they cancel out to 0? Would Na give away the same # of electrons that O needs?. Objectives. Students will be able to: Predict the ions that elements will form
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Admit Slip • What ions would Na and O create? • If you put Na and O’s ions together, would they cancel out to 0? • Would Na give away the same # of electrons that O needs?
Objectives • Students will be able to: • Predict the ions that elements will form • Predict the ionic compound that two elements will form
Today’s Agenda • Admit Slip • Notes • Classwork • Exit Slip Product: Notes, Classwork, Exit Slip Homework: Problems # 1-5
Ionic Compounds 10/31/13 • Ionic compoundsare formed when a metal atom gives its valence electrons to a nonmetal atom. • Both of the atoms will now have a full valence shell like the noble gases which will make them stable. • Thepositive (+) metal ion is attracted to the negative (-) nonmetal ion and this attraction is called an ionic bond. Li becomes Li+1 F becomes F-1 Li+1 + F -1 LiF
When creating an ionic compound, the positive(+) and negative (-) charges cancel out to 0. • The positive and negative charges must be equal because the number of electrons being given by the metal need to be equal to the electrons being taken by the nonmetal. Example: • K+1 and Cl-1 will form KCl because +1 and -1 cancel out to 0.
Example 1 B and N • B wants to give away 3 e- • B becomes B+3 • N wants to get 3 e- • N becomes N-3 You need 1 (+3) charge and 1 (-3) charge to cancel out to 0. BN
Example 2 K and O • K wants to give away 1 e- • K becomes K+1 • O wants to get 2 e- • O becomes O-2 You need 2 (+1) charges to cancel out the -2 charge. K2O
Example 3 Mg and F • Mg wants to give away 2 e- • Mg becomes Mg+2 • F wants to get 1 e- • F becomes F-1 You need 2 (-1) charges to cancel out the +2 charge. MgF2
Example 4 Al and O • Al wants to give away 3 e- • Al becomes Al+3 • O wants to get 2 e- • O becomes O-2 You look for the common multiple of 2 and 3, which is 6. The charges will cancel out when you have 2 (+3) charges and 3 (-2) charges. Al2O3
Ionic Compound Shortcuts: • Multiply the +1 or -1 charge by the larger number to make them equal. • Or switch the charge numbers to find the subscripts, the smaller numbers written low that tell how many ions/atoms of each type are in the compound. • You always write the metal positive + ion (cation) before the nonmetal negative - ion (anion) • Na+1 and Cl-1 will form NaCl, not ClNa.
After the Notes • Complete your worksheet. • Ask Questions if you need help! • Do your Exit Slip by yourself! Start your homework!