Question

list the electron configuration for the metsl ions used in the compound you test (to discover the different frequencies of light that is emitted by various metallic ions

Answer 1

Usually we perform the flame test for detection of elements having different frequencies.

NOTE: Flame test is performed by first cleaning the platinum wire and then dipping it into concentrated HCl and later holding on to the bunsen burner flame. This process has to be repeated until the wire doesn't produce any color. Later, the same wire has to be dipped in small amount of HCl and a small quantity of the compound to be tested. Again place the wire on the flame and the colors to the flame determines the element present in the compound.

Below is the list of elements which produce the colors to the flame. Flame test is normally shown by the group 1 and 2 elements.

Lithium- Red

Sodium-Strong Orange/yellow

Potassium- Pink/ lilac

Calcium-Orange Red

Barium-Pale green

The colors are observed because the electronic configurations of the elements change, after excitation of the atom by very strong heating. As they fall to the lower level, energy is given out as light. Each jump requires a certain amount of energy to be released as light and each of which corresponding to the certain frequency. Thus, a spectrum of lines is produces some of which in the visible part (can be seen through the eyes), and some in the UV region (which cannot be seen).

For instance, in the case of sodium, or any other metal ions, the jumps requires high energy and thus comes under UV region. The color which can be seen is due the electron falling from the higher to lower level in the metal atom.

Lithium (1s²2s¹) - Li⁺¹  (1s²)

Sodium (1s²2s²2p⁶3s¹) -Na⁺¹ (1s²2s²2p⁶)

Potassium (1s²2s²2p⁶3s²3p⁶4s¹) -K⁺¹ (1s²2s²2p⁶3s²3p⁶)

Calcium (1s² 2s² 2p⁶ 3s² 3p⁶4s²)- Ca²⁺ (1s² 2s² 2p⁶ 3s² 3p⁶)

Barium ([Xe]6s²) -Ba²⁺ [Xe]