Question 1: A flame test involves heating a metal salt to observe the characteristic color it produces in the flame. This color arises because electrons in the metal atoms absorb energy and jump to higher energy levels, then release light as they return to lower levels. Which scientific principle explains this phenomenon?

Answer: Electron excitation and emission of specific wavelengths of light

Question 2: List three common metal ions tested using flame tests and their typical flame colors.

Answer: Sodium - Yellow, Copper - Green/Blue, Lithium - Crimson

Question 1: Why is it important to clean the metal wire or loop before performing a flame test?

Answer: To remove any previous metal residues that could contaminate the results.

Question 2: Explain why different metal ions produce different flame colors.

Answer: Different metal ions have unique electron configurations, causing them to emit specific wavelengths of light when their electrons return to lower energy levels.

Question 1: A student observes a flame color that matches the known emission spectrum of sodium. If the wavelength of the sodium yellow flame is approximately 589 nm, what is this wavelength in meters?

Answer: 5.89 x 10^-7 meters

Question 2: During an experiment, a sample produces a flame color that is a mix of red and crimson. Which metal ion is likely present? Support your answer with the specific color description.

Answer: Lithium, which produces crimson or deep red flame colors.

Question 1: List two safety precautions students should follow when performing flame tests in the laboratory.

Answer: Wear safety goggles and handle hot equipment with tongs or gloves.

Question 2: Describe the procedure for preparing a metal salt sample for a flame test.

Answer: Dissolve a small amount of the metal salt in distilled water, dip a clean metal wire loop into the solution, then hold the loop in the flame for observation.

Question 1: A student tests three unknown metal salt samples and records the following flame colors: Sample A - Yellow, Sample B - Green, Sample C - Crimson. Match each sample to the most likely metal ion.

Answer: Sample A - Sodium, Sample B - Copper, Sample C - Lithium

Question 1: How are flame tests used in the fireworks industry to produce different colors? Explain briefly.

Answer: Different metal salts are added to fireworks, and when ignited, they produce specific colors based on their flame emission spectra.

Question 1: Describe the process of conducting a flame test for a metal salt, including preparation, safety measures, and how to interpret the results. Discuss the scientific principles involved and potential sources of error. (6 marks)

Answer: To perform a flame test, first clean a metal wire loop and dip it into the metal salt solution. Hold the wire in a clear, non-luminous flame while observing the color produced. Safety precautions include wearing goggles and handling hot equipment carefully. The flame color indicates the presence of specific metal ions due to electron excitation and emission of characteristic wavelengths. Errors can occur from contamination, incomplete cleaning, or using impure samples, which may lead to inaccurate identification.