Periodicity and Chemical Reactivity

Pre-Lab

  1. Draw a diagram that shows the number of energy levels and valence electrons for each of the following metals: Mg, Ca, Sr, Ba
  2. Predict which metal “holds on” to its electrons the tightest. Explain
  3. Predict which metal “holds on” to its electrons the loosest. Explain
  4. Based on your answers to Questions 2 & 3, which metal do you predict to be the least reactive? Explain
  5. Describe and illustrate how each of the metals in Question 1 form ions.
  6. Define precipitate.
  7. Which of the metals in Question 1 would form the most precipitates? Explain

Lab

  • You have available solutions containing Mg+2, Ca+2, Sr+2, and Ba+2 and solutions containing SO4-2, CO3-2, C2O4-2, and CrO4-2.
  • Mg+2, Ca+2, Sr+2, and Ba+2 may or may not react with SO4-2, CO3-2, C2O4-2, and CrO4-2.
  • Devise a procedure in which you will determine if Mg+2, Ca+2, Sr+2, and Ba+2 react with SO4-2, CO3-2, C2O4-2, and CrO4-2.
  • Make a data table in which you will record your observations. You will want to record whether or not each metal ion reacts or doest not react with each of the nonmetal ions. If a metal reacts with one of the negative ions, it will produce a precipitate.

Analysis and Conclusions

  1. Do our observations support your predictions to Pre-lab questions 1 and 7? Explain.
  2. Describe any relationship that you observed between the position of the metals on the periodic table and their degree of chemical activity.
  3. For the metals that did react with a nonmetal ion, write the chemical name and formula for the precipitate formed.
  4. List other properties that would help you establish a more accurate relationship between the position of an element within its family on the periodic table.
  5. Which family of elements would it be hardest to place within their family on the periodic table. Explain.

Periodicity and Chemical Reactivity

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Pre-Lab

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Analysis & Conclusions

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