Introduction:
Although the periodic table may look overwhelming, it is actually very important and neatly organized. The periodic table was written by Dmitri Mendeleev in 1869. The periodic table is an arrangement of elements in groups and periods that are further organized based on their electronic configurations, their chemical properties, and the atomic mass of each element. Furthermore, the elements are broken down by arrangements based on their composition. Metals are located on the left of the periodic table, the metalloids are located in a zig-zag diagonal line down the table. The arrangements of these atoms allowed scientists to study the table, add elements and admire the works of Dimitri Mendeleev. Studying the trends of the periodic table is very valuable because patterns and similarities are noted. For example, all of the elements in certain groups have the same amount of valence electrons. The periodic table is one contains some of the most knowledgeable data in the scientific world, and without it, scientists would have struggled to make discoveries.
Background Information:
Dmitri Mendeleev was a Russian chemist and one of the most intelligent scientists in history. Mendeleev was born on February 8, 1834, to an extremely large Russian family, and was one of seventeen children! He was famous for creating the periodic table, and organizing elements based on their composition, and their reactivity. Although many professors had previously attempted to make the periodic table, Mendeleev incorporated elements that weren’t yet discovered such as germanium and gallium. He identified patterns of “valency” in the electrons. Although everyone remembered most notable for making the periodic table, he was also one of the best suitcase makers in all of Russia. Mendeleev formed the periodic table when he was age thirty-five, which was a very impressive age for this time period. He died in the early twentieth century, however, his contribution was long-lasting.
The goal of the Lab:
The goal of this lab was to classify unknown elements into a correct periodic table based on the properties that were listed. Another goal was to explain electronegativity, atomic radii, and ionization energy, as well to predict properties of the elements based on their correlation in the table. In the second half of the lab, the reactivity of the elements was how they responded was what we were looking for.
Materials:
Materials for Part A & C included the element card set.
Materials for Part B:
Goggles,
2-100mL beakers
2-250mL beakers, Phenolphthalein indicator solution
0.50 grams of calcium turnings
0.50 grams of magnesium ribbon.
Materials for Assessment:
colored pencils
pens
the periodic table outline.
Procedure:
Part A: To begin Part A of the procedure, a set of cards were obtained and each card represented the main group of an element. Then cards labeled Gg, Jj,Rr,Ss,Tt,Vv,Yy,Zz,Ww were all obtained. The cards were next placed in order of increasing atomic mass, then the table was checked by Mr. Heuer. After doing this, the information on the remaining cards was used to arrange them into eight groups and four periods. Furthermore, the properties of the cards were then recorded and explained and how it helped to arrange the cards. Mr. Heuer then confirmed the table was correct before the patterns and trends were listed. Next, the nonmetals, metalloids, and metals were all located on the table, as well as most of the gasses. The work was then checked before starting Part B of the procedure.
Part B: Part B began by adding 100mL of water into each of the two hundred and fifty-milliliter beakers. Second, two drops of phenolphthalein were added into each beaker. Phenolphthalein was then added due to the reason that it turns hot pink in a basic solution. Third, 0.50 grams of calcium was added to one of the beakers. Next, 0.50 grams of magnesium was added to the other beaker. Finally, the observations were recorded.
Part C: First, the Unknown elements were located on the table. The trends on the table were used to predict where the card would be located. The trends were used to make predictions. The first prediction was, to identify what phase the element would be at room temperature. The second prediction was the appearance of the element and what it would be. The next prediction was the ratio to combine with oxygen the element and, finally, the last prediction was the ratio between the element and fluorine combine.
Data:
Conclusion:
After the lab was completed, my partner and I were able to correctly group the elements into the periodic table. The electronegativity on the periodic table shows that as you move across the table, it increases, however, if you move down the table it decreases. These results are opposite for the atomic radii. As you move across the table, the size decreases while moving down the table increases. The ionization characters are the same as electronegativity in the sense that as you to the right, the energy decreases and moving down.
Sources of Error:
Although my partner and I didn’t make any errors throughout the lab it was definitely a possibility. For example, a source of error that may occur incorrectly organizing the elements. Another chance of error that could lead to incorrect results was when the amount of magnesium or calcium that was added. Having too much of either element may alter the data results.