Overview of XRF XRF (X-ray fluorescence) is an analytical technique that verifies the chemical elements found in a material without destroying it during analysis (Pinto 2018). Specialised equipment known as XRF analysers establish a sample’s chemistry by quantifying the extent of fluorescence emitted following the excitation of the material by X-ray radiations. During XRF, a sample (can be in solid or liquid form) is exposed to high-energy X-rays originating from a regulated X-ray tube. When radiations possessing energy that exceeds the binding energy of atomic K or L shells hit the atoms in the material, an electron from the innermost orbital shells is displaced, which destabilises the atom (Leyden 2018). As the atom returns to stability, the void left by the excited electron is filled with another electron from an orbital with higher energy. Fluorescent X-rays are emitted during this transition. Therefore, the irradiation of a chemical element with X-rays generates a set of distinct fluorescent X-rays that are unique to a given element. This array of fluorescence is referred to as a fingerprint and can be used to identify various chemical elements (Klockenkämper & Von Bohlen 2014). As a result, XRF spectroscopy can be used to conduct quantitative and qualitative investigations of material composition (Rouillon & Taylor 2016). Experimental Procedure About 20 unknown, numbered salt samples were provided to the class. One unknown sample (number 16) was chosen and used for individual analyses. An XRF film was placed over one part of a cup. A second part of the cup was then put on top of the film and used to push it down. A weighing balance was cleaned to remove any impurities that could have altered the accuracy of the measurements after which approximately 2.48 grams of the unknown sample were weighed. The required weight was supposed to be between 2 and 3 grams. The weighed salt sample was then put in a sample press machine to be flattened after which the height of the flattened sample was measured and found to be 4 cm. The sample was then labelled by indicating the sample number, weight, name of the student and height after flattening. These values were indicated on the cover of the cup. The prepared sample was then put in the RIGAKU XRF machine for analysis together with additional unknown samples prepared by other students. The results of the analyses were later provided by the instructor to facilitate the writing of the report. Results Table 1 below shows the concentrations of various trace elements in different salt samples. The individual sample is highlighted in red. It was noted that sodium (Na) was the main cation with a concentration of 521,000 parts per million (ppm), whereas chloride (Cl) was the predominant cation with a concentration of 363,000 ppm. Sample 16 had the second highest concentration of sodium. Trace elements that were present in sample 16 included aluminium at 6420 ppm, bromine at 57.4 ppm, calcium at 119 ppm, chromium at 10 ppm, copper at 4.91 ppm and potassium at 112 ppm. Other chemical elements that were found in the salt specimen included phosphorous, rubidium, silicon and stannum at concentrations of 640, 4.29, 616 and 50.6, respectively. Trace elements that were detected