Name ______
Ions & Ionic Charges
USING THE PERIODIC TABLE TO FIND IONIC CHARGES
Finding the ionic charge of a metal: In many cases, the ionic charge is equal to the number of valence electrons in the outer shell. The metal gives electrons, so it will always get a positive (+) charge.
Figure A shows an example.
Potassium has one valence electron which it will give away to become stable.
The ionic charge of potassium is 1+
K1+
Finding the ionic charge of a nonmetal: Find the amount of valence electrons the nonmetal has in the outer shell and determine how many more it needs to become full—to get to 8. That number is the ionic charge number. The nonmetal takes electrons, so it will always get a negative (-) charge.
Figure B shows an example.
Oxygen has 6 valence electrons so it needs 2 more to have 8 and be stable.
The ionic charge of oxygen is 2-
O2-
PRACTICE
1. How many valence electrons does beryllium have? ______
2. Beryllium is a: metal or nonmetal? ______
3. Beryllium gives or takes electrons? ______
4. How many electrons can beryllium give? ______
5. What is the ionic charge of beryllium? ______
1. How many valence electrons does sulfur have? ______
2. Is its outer shell full? ______
3. How many electrons are needed to make it full? ______
4. Sulfur is a metal or a nonmetal? ______
5. Sulfur gives or takes electrons? ______
6. How many electrons are taken? ______
7. What is the ionic charge of sulfur? ______
1. How many valence electrons does iodine have? ______
2. Is its outer shell full? ______
3. How many electrons are needed to make it full? ______
4. iodine is a metal or a nonmetal? ______
5. iodine gives or takes electrons? ______
6. How many electrons are taken? ______
7. What is the ionic charge of iodine? ______
COMPLETING SENTENCES
Complete the sentences using the following word bank.
1. Metals link up with, or bond to, nonmetals to form ______.
2. When forming compounds, metals ______and nonmetals
______electrons.
3. The number of electrons an atom gives or takes is called its
______.
4. An ionic charge is written as a ______followed by a ______.
5. The number tells us ______electrons an atom gives or takes.
6. The sign tells us whether the atom ______electrons.
7. An atom with a (+) charge ______electrons.
8. An atom with a (-) charge ______electrons.
9. A nonmetal will take enough electrons to fill its ______.
10. A complete outer shell usually has ______electrons.
MATCHING
Match the two lists by writing the correct letter on the line provided.
1. ______compounda) # of e- given or taken
2. ______8 outer shell e-b) gives electrons
3. ______ionic chargec) a metal and nonmetal bonded
4. ______+ iond) takes electrons
5. ______- ione) needed for atom to be stable
COMPLETE THE CHART
Complete the chart by filling in the missing information.
Element / Symbol and Charge / Metal or Nonmetal? / Gives or takes e-? / How many e- given or taken?1 / oxygen / O2-
2 / calcium / Ca2+
3 / aluminum / Al3+
4 / bromine / Br1-
5 / nitrogen / N3-
6 / zinc / Zn2+
7 / lithium / Li1+
8 / sulfur / S2-
9 / phosphorus / P3-
10 / silver / Ag1+
TRUE OR FALSE
In the space provide, write T or F to indicate if it’s true or false.
____ 1. Ionic charge is the number of electrons in an atom.
____ 2. Every element has the same ionic charge.
____ 3. Some elements have no ionic charge.
____ 4. An atom with a (+) ionic charge gives electrons.
____ 5. An atom with a (-) ionic charge takes electrons.
____ 6. An atom with a 2+ ionic charge takes 2 electrons.
____ 7. An atom with a 2+ ionic charge gives 2 electrons.
____ 8. An atom with 6 valence electrons can give 3 electrons.
____ 9. An atom with 7 valence electrons has an ionic charge of 1-.
____ 10. An atom with 7 valence electrons can take 1 electron.
IONIC FORMULAS
Use SJ 14 and your periodic table to determine ionic formulas.On the left, do the drawing method, on the right do the shortcut method.
1) sodium fluoride
2) lithium oxide
3)magnesium sulfide
4) boron chloride
5)boron sulfate (use p. 60 for polyatomic ionic charge)
6) lithium carbonate (use p. 60 for polyatomic ionic charge)