Prelab

Nombre:________________________________________________________

Grupo: ____________

Evidence Name: Prelab assignment “Flame test” Objective: Experimental procedure to test the behavior of atomsin respect to the energetic changes

Prelab assignment “Flame test”
Introduction When the elements are heated to high temperatures, some of their electrons are excited and they jump form an energylevel to another with higher energy. These electrons can return at lower levels, releasing the excess of energy in form of light packages called quantums or photons. The arrangement of electrons inan atom determines the size of the quantum jump and thus the energy and colors of the collection of photons emitted, known as the emission spectrum. In this way, the emission spectrum serves as a“fingerprint” of the element to which the atoms belong. We can view the emission spectrum of colors all at once with the naked eye. It will appear to be one color, which we will carefully describe. It isalso possible to separate the colors of the emission spectrum by using a spectroscope, which bends light of different energy levels differently. Problem There are three substances (A, B, C) that havelost their labels, but it is known that all contain inorganic salts, composed by nitrate ions and a metallic element. How could you identify the metallic element that is part of each one of the unknownsalts, with the materials that are available in the laboratory? (Answer this question with a hypothesis)

Materials and reactants • Bunsen burner • Copper (II) nitrate solution • Sodium nitratesolution • Calcium nitrate solution • Potassium nitrate solution • Lithium nitrate solution • Strontium nitrate solution • Unknown substance A • Unknown substance B • Unknown substance CNombre:________________________________________________________

Grupo: ____________

PRELAB Investigation tasks Write the formulas of the substances that will be tested.

1. List the colors of the...