Flame Tests Of Metal Cations Science Lab Template printable pdf download

Flame Tests Of Metal Cations Science Lab Template

Flame Tests of Metal Cations

Objectives

The objectives of this lab are to:

a) Perform flame tests of metal cations in order to observe their characteristic colors,

b) Match the flame colors observed to an appropriate wavelength of visible light, and then perform

calculations to determine the frequency and energy of the emitted photons,

c) Relate these results to the types of electronic transitions occurring in these elements,

d) Practice writing electron configurations for these (and other) elements.

Background

Electromagnetic radiation is composed of perpendicular waves oscillating in the electric and magnetic

fields (through space or matter). These waves are characterized by their wavelength (

) and frequency

(

). Wavelength is defined as the distance between successive crests (or troughs) on a wave, and is

measured in meters. Frequency is defined as the number of waves that pass a given point every second,

and is measured in 1/seconds, or Hertz (Hz).

All electromagnetic waves travel at the speed of light (c), or 2.998 x 10

m/s. The relationship between

the wavelength, frequency and speed of an electromagnetic wave is given by the equation:

Electromagnetic radiation also occurs as discreet packets of energy (or quanta) called photons. The

energy per photon (in Joules) is given by the equation:

= h

photon

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•

Here, h is Planck’s constant, which has a value of 6.626 x 10

Visible light is the most familiar example of electromagnetic radiation. Differences in the wavelengths

of visible light are manifested as different colors, shown in the Color Spectrum below (colors can be

seen in the PDF document on-line). Other examples of electromagnetic radiation include X-rays,

ultraviolet light, infrared light, microwaves and radio waves.

400 nm

500 nm

600 nm

700 nm

UV ← Violet

Red → IR

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Flame Tests Of Metal Cations Science Lab Template