10 (B410U10-1) Examiner only 12. David said that sodium compounds give a yellow flame test because the heat makes the atoms move faster. He also said that the yellow flame was the sodium absorption spectrum consisting of one line because the atoms take in light of just one energy. (a) Discuss how far you agree with David’s statement and correct any errors which he has made. You should include the chemical principles involved. [6 QER] (b) A white solid is known to be either a magnesium or a potassium compound. Describe how you could carry out a flame test to identify the metal ion present. You should include the expected result for each compound. [2] © WJEC CBAC Ltd. Turn over. 11 Examiner only (c) (i) A line in a visible spectrum was observed at a wavelength of 500 nm. Calculate the energy involved in the formation of this line. Give your answer with its unit and in standard form. [3] Energy = ............................................... Unit = ............................................... (ii) A line in another spectrum was found to have a higher energy associated with its formation so that it was no longer visible. In which part of the electromagnetic spectrum would it be found? [1] © WJEC CBAC Ltd. 12 (B410U10-1)