Chemistry

posted by .

We did a flame test today to see what substances produce what colors when burned.
Can you please explain...

Why each of the different elements have a different atomic emission spectrum?

Would the flame tests be useful for detecting individual elements present in a mixture of elements?

  • Chemistry -

    Atoms usually exist in their "so-called" ground state; i.e., the lowest energy. When an atom is placed in a flame, the energy from the flame is enough to make an outer electron (say from a Na atom) move from the 3s level to a higher energy level. After a short period of time the electron falls back to its initial 3s level. When it does that it releases the same amount of energy it absorbed in the first place. For the Na atom that energy is in the yellow part of the spectrum and that's the color one sees with Na. For other atoms the color is different because it takes a different amount of energy to move an outer electron of K than it does for Na. In fact, no two elements have the same spectrum because each element moves different electrons to and from different energy levels.

    Flame tests are extremely helpful in identifying SOME (but not all) elements. Ba, Na, K, Sr, Li, Cu, Ni, and a few others have characteristic flame emission spectra. The spectrum of some elements interferes with the spectrum of other elements; e.g., K can not be detected in the presence of Na without a special technique.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Flame Colors - Chemistry

    I've searched the internet but I can't find out what color flame a Nickel (or even better NiSO_4) solution will produce when burned. As well, does Aluminum (Al(SO_4)_3 ) have a flame color from the flame test?
  2. Chemistry

    Regarding Flame Tests, why do you have to subject the sample to a flame?
  3. Chemistry

    Regarding Flame Tests, why do you have to subject the sample to a flame?
  4. astronomy

    on a domestic gas cooker the temperture in the hottest part of the flame is about 2200k.if salty eater is spilled in the flame then it becomes yellow-orange.measurements with a spectrometer show the presence of an emission line at …
  5. Chemistry

    Hii! I have a question: So the flame photometer uses a natural gas flame (1800 oC), what if it uses acetylene - nitrous oxide flame which is ~3000 oC, what would happen to the emission intensities?
  6. Physics - Hydrogen Emission spectrum

    a) Describe the emission spectrum of a hydrogen discharge tube b) Explain why different color lines appeared in different position in the spectrum. Use a suitable atomic model to help construct your answer. c) Explain how do you decide …
  7. Chemistry -Flame colors (check+help)

    What are the characteristic flame color for sodium, potassium, barium, copper, strontium, and calcium?
  8. chemistry ------ flame test-------------

    Did the nitrate ion effect the color emission of the solution ?
  9. Chem

    What pairs of ions produce similar colours in the flame test?
  10. Chemistry

    Can a flame test and emission spectrum test be used to identify a mixture with two or three elements?

More Similar Questions