Name___________________ 1/5/2012 Electron Configuration of Ions 1) Group the following elements into cation forming and anion forming elements. Fluorine, Sodium, Nickel, Cobalt, Oxygen, Sulfur, Magnesium Cation forming ________________________________ ________________________________ ________________________________ ________________________________ Anion forming ________________________________ ________________________________ ________________________________ ________________________________ 2) Next to each element above, write how many electrons that element gains or loses to form an ion with a full octet. 3) What is the net charge on each of these atoms before they form ions? ____ 4) What is the net charge on ions of each of the following elements? a. Fluorine _______________ b. Sodium _______________ c. Nickel _______________ d. Cobalt _______________ e. Oxygen _______________ f. Sulfur _______________ g. Magnesium _______________ Chemical Symbols for Ions We can represent an ion symbolically with its element’s chemical symbol and its net charge For example, potassium is in group 1, so it has 1 valence electron. Potassium loses 1 valence electron to acquire a full octet. This leaves potassium with a +1 charge K e- + K + K+ is how we write a potassium ion. If potassium lost two electrons, how would you write the ion? _____ If potassium gained an electron, how would you write the ion? _____ 5) Represent each of the following ions symbolically a. Fluoride _______________ b. Sodium _______________ c. Nickel _______________ d. Cobalt _______________ e. Oxide _______________ f. Sulfide _______________ g. Magnesium _______________ Ionization Reactions You saw an example of an ionization reaction above. Potassium gives off an electron to form a potassium ion (K+) K e- + K+ Non-metals gain electrons to form anions Cl + e- ClWrite ionization reactions for the following elements a. Fluorine _______________ b. Sodium _______________ c. Nickel _______________ d. Cobalt _______________ e. Oxygen _______________ f. Sulfur _______________ g. Magnesium _______________ Electron configurations of ions We’ve practiced two methods of writing electron configurations for atoms Sodium: We can apply the same principles to write an electron configuration of ions. Pay careful attention to how many electrons an ion has before writing its electron configuration. Hint: Ions must have full valence shells (i.e. full outermost s and p orbitals) Write the electron configurations in two ways for each of the following ions _________________________ Fluorine _________________________ Sodium _________________________ Nickel _________________________ Cobalt _________________________ Oxygen _________________________ Sulfur _________________________ Magnesium Reflection questions 1) From which orbitals do cobalt and nickel atoms lose electrons when they form ions? 2) Go through the seven electron configurations you drew. Next to each, write the element that has the same electron configuration (i.e., when it’s atoms have an equal number of protons and electrons). For which elements is this impossible?