FLAME COLOR OF METALSChristine Dyan RiojaDe La Salle University-DasmariñasDasmariñas, Cavite PhilippinesABSTRACTThe experiment about flame color of metals demonstrates how electrons jump into their excitedstate from their ground state as it came in contact with heat. As it return to its lower energy state,it emits the absorbed energy in the form of light. A platinum or nichrome wire was dipped into aconcentrated HCL and was heated to clean it. The wire was dipped into different salt solutionsand heated in order to determine the metallic ion’s color and wavelength. Metal ions emitting aviolet-colored flame has the largest amount of energy while those that emit red-colored flamehave the least amount of energy.INTRODUCTIONAn a tom is the sma l les t par t i c le o f an e lement , wh ich can ex is t and s t i l l have theproperties of the elementElectrons determine the chemical properties of atoms. The electrons in an atom exist inlayers called shells or energy levels. The negatively charged particles of an electron are kept inorbit in the energy levels. Normally, atoms do not emit radiation but there are ways of causingradiation to be emitted. The simplest of these is to heat the atoms. When an atom is heated, itabsorbs energy causing its electrons to get excited to positions of higher potential energy farther away from the nucleus. At this state, the atom becomes unstable. When an electron goes back toits ground state, it radiates the absorbed energy in the form of light, which has a characteristicwavelength. This is the basis of the flame test used to identify the element. The quantity of energyabsorbed will account for the presence of a spectral line. The emission spectrum may be used todetect the presence of an element in both qualitative and quantitative way. Elements may oftenbe recognized by the color they impart to a flame.MATERIALS AND METHODSA platinum or nichrome wire was dipped into a concentrated HCL. The wire was heatedin to the f lames ho t tes t reg ion un t i l t he re was no v is ib le co lo r . The c lean ing p rocedure was repeated as necessary. On a watch glass, a few crystals of CaCl2 were added on to 2 or 3 dropsof distilled water. It was stirred until it was dissolved. The clean wire was dipped into a saltsolution and was returned to the hottest part. The flame color was then noted. Using other salts,namely KCl, NaCl, CuCl2, LiCl, SrCl; the process was repeated.

RESULTS AND DISCUSSIONAs the salt solutions were exposed to the hottest region of the flame, the atoms of thefollowing metal ions jumped into their excited states and immediately emitted different kinds of color according to their own characteristic line spectrum.For this experiment, necessary computations were needed such as the energy,frequency of light, and wavelength. Below are the formulae and references used in theexperiment.Equation 1: E=hc/ ΛEquation 2: E=hvWhere:E

-energy of lightC-speed of light (3.00 x108m/s)H-Planck’s constant (6.63 x10-34J-s)V-frequency of lightΛ= wavelength2TABLE 1. CORRELATION BETWEEN WAVELENGTH AND COLORw a v e l e n g th   ( n m ) C o lo r3 8 0 -4 3 5 V io l e t 43 5 -4 8 0 B lu e 4 8 0 -4 9 0 G r e en -b l u e 4 9 0-5 0 0 B l u e-g r e en 5 0 0 -5 6 0 G re e n 5 6 0-5 8 0 Y e l l ow -g r e en 5 8 0 -5 9 5 Y el l o w 59 5 -6 5 0 O ra n g e 61 0 -7 5 0 Re d The table below shows the complete data of results after doing the experiment andsolving for the necessary values.

TABLE 2. RESULTSM e t a l  I o n C o l o r V  ( H z ) Λ   ( n m) E   ( J )C a l c i u m  ( C a ) O r a n g e 4 . 4 1   x 10-46 8 0   n m 2 . 9 3   x 1 0-37JC o p p e r  ( C u ) G r e e n 6 . 1 9   x1 0-44 8 5   n m 4 . 1 0   x 1 0-37JS o d i u m  ( N a ) Y e l l o w 4 . 8 2   x1 0-46 2 2 . 5   n m 3 . 2 0   x 1 0-37JL i t h i u m  ( L i ) R e d 4 . 8 2   x1 0-46 2 2 . 5   n m 3 . 2 0   x 1 0-37JP o t a s s i u m  ( K ) V i o l e t 4 . 8 2   x 1 0-46 2 2 . 5   n m 3 . 2 0   x 1 0-37JS t r o n t i u m  ( S r ) R e d 4 . 4 1   x 1 0-46 8 0   n m 2 . 9 3   x 1 0-37J

In this experiment, we were able to analyze metallic ions in salts with the use of flametest. We were also able to determine the metal that emitted the largest amount

of energy which isPotassium ( K) and the metal that emitted the least amount of energy which is Lithium (Li) andStrontium (Sr).REFERENCES(1)Samonte, J.L.; Figueroa, L.V. General Chemistry Laboratory Manual 3rdedition.(2)Lontok, B.M.; Montessa D.V. A Laboratory Manual in General Chemistry 3rdedition