12/17/2010

There are very many elements in the world. Some occur naturally, and others are man-made. Elements are used every day in all kinds of different ways. Strontium is an element with many characteristics, chemical properties, and interesting facts.
The element strontium was first discovered by Adair Crawford who noticed a different element when observing barite in 1790. He named the new discovery strontia.
He named it this because strontia is a lead mine in Scotland, from which the element was found. Strontium the element was discovered by Klaproth and Hope eight years later. In
1808 however, Humphrey Davy used electrolysis to isolate strontium into a metal for the first time (“Strontium, Chemical Element”). The atomic symbol for strontium is “Sr”.
Strontium’s atomic number is 38, and the atomic mass is 87.620 amu. It is classified as an alkaline earth metal (Emsley). The melting point for strontium is 769.0 degrees
Celsius. The boiling point for strontium is 1384.0 degrees Celsius. Strontium’s natural phase is solid, and is a silvery metal (“The Element Strontium”).
Generally strontium is found in combination with other elements, or compounds.
This is because it violently reacts with air, so if strontium occurred naturally it would burn off instantly (“Strontium (Sr)…”). Strontium is an element that is typically found in the Earth’s crust. It is roughly as abundant as fluorine, and barium (Baker). Strontium naturally occurs in 0.034% of the Earth’s igneous rock (“The Element Strontium”). Some important compounds of strontium are strontium nitrate and strontium carbonate. They are mostly used for pyrotechnics (“Strontium (Sr)…”). When strontium is found it is usually found in Mexico, Spain, Turkey, and Iran. There is some found in the United
States, but not as much as those countries (“Strontium, Chemical Element”).

Strontium’s atomic structure is as follows. The center has thirty-eight protons, and usually fifty neutrons. There are five different energy levels. The fist energy level has two electrons. The second, level has eight electrons. The third energy level has a total of eighteen electrons. There are eight electrons in the fourth energy level, and two electrons in the fifth. Strontium’s filling order is 2-8-18-8-2, this tells where the electrons are throughout the energy levels. The electron dot diagram has a dot on the left, then “Sr”, there is a dot on the right (See appendix A) (“The Element Strontium”). The electron configuration for strontium is [Kr] 5s
2
(“Strontium (Sr)…”). There are very many isotopes of strontium (See appendix B), but the most common isotopes of strontium are
84
Sr,
86
Sr,
87
Sr,
88
Sr, because they are stable isotopes (“Strontium.”
Third Millennium…
).
88
Sr is the most abundant isotope 82.6% of strontium is
88
Sr. Strontium’s oxidation numbers range from 0 to +2. +2 is the highest common oxidation number, and 0 is the lowest common oxidation number (
“Strontium.”
Periodic…) . There are eleven radioisotopes, or isotopes that are radioactive. Sr
80
, Sr
81
, Sr
82
, Sr
83
, Sr
85
, Sr
89
, Sr
90
, Sr
91
,
Sr
92
, Sr
93
, Sr
94
, and Sr
95
are the radioactive isotopes of strontium (“Strontium
Radioisotopes”).
There are several reactions that can occur when strontium comes into contact with other elements. The most common reaction is when strontium is combined with air. Air is a mixture of many gasses, but when strontium is exposed to oxygen this reaction occurs,
O
2
+ 2Sr

2SrO, which is a synthesis reaction creating strontium oxide. Another common reaction is between strontium and nitric acid. The reaction formula is Sr +
HNO
3
 H
2
+ Sr(NO
3
)
2
, which is a single replacement reaction forming hydrogen gas and strontium nitrate. When strontium is exposed to hydrochloric acid the reaction

formula looks like this Sr + HCl

H
2
+ SrCl
2
. This reaction is a single replacement reaction, and the products are hydrogen gas and strontium chloride (“Strontium”
Periodic… ).
The method for isolating strontium has not changed since it was originally isolated. It was originally isolated by Humphrey Davy using electrolysis. He took molten strontium chloride, and ran an electric current throughout the liquid. This separated the strontium from the chlorine, isolating the strontium (“The Element Strontium”).
There are many industrial, medical and miscellaneous uses for strontium.
Strontium is used in industrial alloys. Alloys are mixtures of metals which have different properties than their parent metals. They are painted on other metals that make the metal stronger, which is very useful for buildings. There are some medical cements being based off strontium’s properties. These cements will be used in arthroplasty. That means that strontium is being used to make better cements for joint replacements (Clarkin).
Strontium has been experimented with in order to increase bone density of humans. The results concluded that with the drug, there was an increase in bone density; people given the placebo had a decrease in bone density. This shows that strontium can be useful in the medical field (“Strontium” Third Millenium… ). Another use for strontium is to color glass the color red (Baker). Strontium is a perfect candidate for coloring fireworks. It burns red, which is a common color in fireworks. It burns rapidly and dies fast which is good for fireworks so they don’t continue to burn when the embers hit the ground.
Strontium is also used in flares they put more strontium, or make a mixture that will burn red, and bright, and last long (Emsley). Still another use for strontium is chemical tracing.
It can stay in plants even through processing. This can be used to find the geographical

origin of certain plants, and food products (Brunner). Some more uses for strontium include, generating electric currents, removing oxygen in vacuum tubes, flares, and some greases (“Strontium (Sr)”).
Pure strontium is sold, it combusts with the air but it can still be sold. Compounds containing strontium are sold more often than pure strontium. Strontium can have harmful effects on the environment, because strontium has radioactive isotopes.
Strontium is similar to calcium, which can be dangerous because if ingested it goes straight to the bone, and gives off radiation. This mutates the cells, and can cause cancer in the person who ingested the strontium (Baker).
The way to successfully separate silver (Ag), zinc (Zn), and strontium (Sr), is to precipitate them individually. To do this you must have safety goggles test tubes, and an apron. First, take the test tube with the mixture of metals and add a few drops of sodium carbonate. A white solid should form, this is the strontium carbonate. Pour the liquid into another test tube leaving the precipitate in the test tube. Second, take the test tube without the strontium and add a few drops of sodium sulfide. This will form another white solid, this is the zinc sulfide. Pour the liquid into another test tube, and add a few drops of sodium hydroxide to the liquid. This should form a dark brown solid, this solid is silver hydride (See appendix C). To dispose of all these elements place all solids in a beaker, water them down until they can be poured down the sink pour the liquid down the drain also.
In conclusion, strontium is a naturally occurring element, but not purely, that has many isotopes, some of which are radioactive. It has many practical uses in both the industrial field and the medical field. Thus, strontium has many different characteristics,

chemical properties, and other interesting facts. What other element burns brightly with a red flame?

Works Cited
Baker, Lawrence W., and David E. Newton. "Strontium." Chemical Elements . Vol. 3 P-Z.
Detroit, Mich. [u.a.: U.X.L, 1999. 553-58. Print.
Brunner, Marion, et al. “Determination of the geographical origin of processed spice using multielement and isotopic pattern on the example of Szegedi paprika.(.” European Food
Research & Technology (Aug. 2012): 623. Abstract. Gale Virtual Reference Library .
Web. 8 Nov. 2010. <http://find.galegroup.com>.
Clarkin, O. M., et al. “Comparison of an experimental bone cement with a commercial control,
Hydroset.”
Journal of Materials Science: Materials in Medicine (July 2009): 1563.
Abstract. Gale Science in Context . Web. 2 Dec. 2010. <http://find.galegroup.com>.
"The Element Strontium." The Periodic Table . 2005. Web. 28 Nov. 2010. <http://www.periodictable.org.uk>.
Emsley, John. "Strontium." The Elements . Oxford: Clarendon, 1991. 180-81. Print.
"Strontium." Periodic Table of Elements and Chemistry . Web. 12 Dec. 2010.
<http://www.chemicool.com>.
"Strontium." The Third Millennium Online!
Web. 14 Dec. 2010. <http://www.3rd1000.com>.
"Strontium (Sr) - Chemical Properties, Health and Environmental Effects." Water Treatment and
Purification - Lenntech . Web. 12 Dec. 2010. <http://www.lenntech.com>.
"Strontium, Chemical Element - Overview, Discovery and Naming, Physical Properties,
Chemical Properties, Occurrence in Nature, Isotopes." Chemistry: Foundations and
Applications . Web. 12 Dec. 2010. <http://www.chemistryexplained.com>.
"Strontium Radioisotopes." Online Doctor - Ask a Doctor over Live Chat . Web. 15 Dec. 2010.
<http://www.healthcaremagic.com>.

Appendix
Apendix A
Isotopes Atomic Mass
Sr79
Sr80
Sr81
Sr82
Sr83
Sr84
Sr85
Sr86
Sr87
Sr88
Sr89
Sr90
Sr91
Sr73
Sr74
Sr75
Sr76
Sr77
Sr78
Sr92
Sr93
Sr94
Sr95
Sr96
Sr97
Sr98
Sr99
Sr100
72.966
73.956
74.95
75.942
76.938
77.9322
78.9297
79.9245
80.9232
81.9184
82.9176
83.9134
84.9129
85.9093
86.9089
87.9056
88.9075
89.9077
90.9102
91.911
92.914
93.9154
94.9194
95.9217
96.9261
97.9285
98.933
99.935
Half-Life
> 25 ms
> 1.2 ms
71 ms
8.9 seconds
9 seconds
2.5 minutes
2.25 minutes
106.3 minutes
22.3 minutes
25.55 days
32.41 hours
Stable
64.84 days
Stable
Stable
Stable
50.53 days
28.78 years
9.63 hours
2.71 hours
7.423 minutes
75.3 seconds
23.9 seconds
1.07 seconds
429 ms
0.653 seconds
0.269 seconds
202 ms

Sr101
Sr102
Sr103
Sr104
Sr105
100.941
101.943
102.949
103.952
118 ms
69 ms
> 150 ns
> 150 ns
Appendix B (“Strontium”
Periodic…
)
Appendix C