Introduction
The purpose of this experiment was to determine the similarities and differences in the chemical and physical properties of elements and elemental groups. This was achieved by the observation and comparison of chemical reactions of different elements.
Results
Group IA
Reactions in Air:
A piece of lithium, sodium, and potassium we cut with a spatula and introduced with oxygen. The elements appeared to be metallic at first, but over time a white color formed where the element was cut. The balanced chemical reactions for these metals in air are as follows:
4Na(s) + O2(g) 
2Na2O(s)
4K(s) + O2(g) 2K2O(s)
4Li(s) + O2(g) 2Li2O(s)
Potassium was the fastest element to have this reaction Sodium was in the middle and Lithium was the slowest.
Reactions in Water:
Pieces of the alkali metals were placed into separate beakers of distilled water. Lithium and sodium quickly dissolved in the water, which created gas emissions. Potassium sparked and lit on fire and created gas when it touched the water. All three alkali metals left white precipitant at the bottom of the beaker. The pH balances were then tested to find if the solution was basic or acidic.
2Na(s) + 2H2O(l) 2Na(OH)(aq) + H2(g)
2K(s) + H2O(l) 2K(OH)(aq) + H2(g)
2Li(s) + 2H2O(l) 2Li(OH)(aq) + H2(g)
The pH paper showed a basic pH for the alkaline earth metals. This is because alkaline earth metal’s valence electrons only have one electron so the atom easily gives that electron away.
If cesium was added to water it would react the same as potassium; that as soon as it touched water it would ignite and explode, but the reaction may be stronger.
The reactivity of these metals increase as you go down the group. As the atom grows larger it becomes more reactive since the electrons are farther away from the nucleus.
Group IIA
Reactions in Water:
Pieces of solid magnesium and calcium were put in test tubes of water. Magnesium had no reaction with room temperature water or with boiling water. The calcium bubbled and formed gas and white precipitate. The pH balances were then tested.
Mg(s) + H2O(l) 
NR
Ca(s) + 2H2O(l) Ca(OH)2 + H2(g)
Reactions in Hydrochloric Acid:
Magnesium and calcium were placed in test tubes with hydrochloric acid. Both metals bubbled. The magnesium completely dissolved, while the calcium formed a white precipitant at the bottom of the test tube. The pH was tested.
Mg(s) + 2HCl(aq) 
MgCl2(aq) + H2(g)
Ca(s) + 2HCl(aq) 
CaCl2(s) + H2(g)
Reactions in heat/oxygen:
Two more pieces of the alkaline earth metals were subjected to heat and oxygen. Each piece of metal ignited and burned. The calcium took longer to ignite then the magnesium. The magnesium was then placed into water and the pH was then tested.
2Mg(s) + O2(g) 
2MgO(s)
MgO(s) + H2O(l) Mg(OH)2(aq)
2Ca(s) + O2(g) 2CaO(s)
CaO(s) + H2O(l) Ca(OH)2(aq)
Calcium is more reactive than the magnesium, but they had similar reactions and pH.
They vary only slightly. Most of the reactions were the same but were slightly stronger with the calcium and the calcium oxide reacted stronger than the magnesium. The elements are more reactive as one desends the column.
The reactions of this group were different, but just as strong as those done with the IA group. They were less explosive, but had impressive reactions.
Group IIIA
Reactions in Water:
Boron and aluminum were placed into test tubes of water. The aluminum created effervescence while the boron had no reaction.
2Al(s) + 6H2O(l) 2Al(OH)3(aq) + 3 H2(g)
B(s) + H2O(l) NR
Reactions in Hydrochloric Acid:
The same was done only instead of water the elements were introduced to hydrochloric acid. The aluminum produced effervescence and the boron had no reaction.
2Al(s) + 6HCl(aq) 2AlCl3(aq) + 3H2(g)
Br(s) + HCl(aq) NR
Reactions in Sodium Hydroxide:
A piece of aluminum and of boron were placed into a test tube of sodium hydroxide. The aluminum created effervescence and the boron had no reaction.
2Al(s) + 2NaOH(aq) + 6H2O 2NaAl(OH)4 (aq) + 3H2(g)
Ba(s) + NaOH(aq) NR
Boron is not active compared to aluminum. Aluminum is beneath boron, which means it’s larger in size and more reactive.
The elements became less reactive in water and are become more acidic then basic, the farther towards the right side of the periodic table they are.
Group IVA
Reaction in Water:
A piece of carbon, tin, and lead were placed in test tubes of distilled water. Five minutes were allowed for a reaction to occur, and none of them reacted in that time.
C(s) + H2O(l) NR
Sn(s) + H2O(l) NR
Pb(s) + H2O(l) NR
Reaction with Hydrochloric Acid:
Another piece of carbon, tin, and lead were placed in separate test tubes which contained hydrochloric acid. Then the test tubes were placed in a hot water bath. Tin and lead slowly created effervescence, while carbon had no reaction
C(s) + HCl(aq) CCl2(aq) + H2(g)
Sn(s) + HCl(aq) SnCl2(aq) + H2(g)
Pb(s) + HCl(aq) PbCl2(aq) + H2(g)
All three elements are non-reactive in water, but as they mix with acids they become reactive. Lead is the most reactive since it is the largest of these elements in this elemental group.
As the element closer to the right side of the table are less reactive since the valence shell progressively fills up, which makes it harder for other atoms to pull electrons from the valence shell.
Group VA
Reactions in oxygen/heat:
A small portion of phosphorus in a deflagrating spoon was ignited by a gas burner. The immited smoke was then put in a flask that had distilled water at the bottom. The captured smoke was mixed with the water, then the pH tested.
P4(s) + O2(g) P4O10(g)
P4O10(g) + 6H2O(l) 4H3PO4(aq)
The pH paper showed that the solution was acidic. It reacted this way because phosphorus is three electrons away from having a full valance electron so it doesn’t react with water easily.
Reaction in Hydrochloric Acid and Water:
Pieces of bismuth were introduced into two test tubes; one contained water and the other contained hydrochloric acid. No reaction occurred.
Bi(s) + H2O(l) NR
Bi(s) + HCl(aq) NR
Group VIA
Reaction in Oxygen/heat:
A small quantity of sulfur was introduced to burner by a deflagrating spoon. Once the sulfur was ignited the spoon was put into a flask which contained a small amount of distilled water in the bottom. The smoke contained was then mixed with the water and the pH balance was tested.
S8(s) + O2(g) 8SO2(g)
SO2(g) + H2O(l) H2SO4(aq)
S8(s) + O2(g) SO3(aq)
SO3 + H2O(l) H2SO3(aq)
The pH paper resulted in being acidic. As with phosphorus, sulfur is closer to having a full valance shell so it’s less reactive and more acidic.
The metallic oxides reacted more explosively with water and the non metallic oxides tended to react by creating gas.
Group VIIA
Reactions in Chlorine Water:
Chlorine water was added to a test tube which contained potassium bromide and another test tube which contained potassium iodide. After observation of the color changes, hexane was added to test to see if an actual chemical reaction occurred. In the potassium bromide: It started yellow color and ended with a pale yellow color. Potassium iodide changed to the color pink.
KBr(aq) + Cl2(aq) 2KCl(aq) + Br2(aq)
2KI(aq) + Cl2(aq) 2KCl(aq) + I2(aq)
The hexane changed the colors to indicate whether a chemical reaction occurred or not. When potassium iodide is mixed with chlorine water a chemical reaction will occur, but not when potassium bromide is mixed with chlorine water.
Bromine water was added to test tubes which contained potassium iodide and potassium chloride. The potassium iodide started out as a brown color and ended with a pink color. The potassium chloride however started out yellow and ended in a yellow color, but still underwent a chemical reaction.
KI(aq) + Br2(aq) KBr(aq) + I2(aq)
KCl(aq) + Br2(aq) KBr(aq) + Cl2(aq)
Based on the results of this experiment it can be concluded that iodine is more reactive than bromine which is more reactive then chlorine. In the experiments iodine separated its-self from the potassium, which means that it would rather be by its self and is more stable than chlorine and bromine.
Discussion
The elements are progressively more reactive farther down the periodic table they are. This is due to the atoms increase in size, which causes the electrons be farther away from the nucleus which makes it easier for other atoms to pull the electrons away. The elements bigger and less reactive on the right side of the table than the left side. The atoms grow in size as the proton numbers increase, but the valence electrons are fuller, which makes it harder for other atoms to pull the electrons away.
As size increases the ionization energy increases, it makes an element less reactive. This is due to the fact that as the valence sub-shell is gets fuller, there are more electrons to pull from the atom.
References
1. General Chemistry Experiments: A Manual for Chemistry 204, 205, and 206, Department of Chemistry, Southern Oregon University: Ashland, OR, 2009
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