Question

Dry Lab Questions Circle the questions that have been assigned 1. What experimental evidence leads scientists to believe that only quantized electronic energy states exist in atoms? 2. a. What is the wavelength range of the visible spectrum for electromagnetic radiation? b. What is the color of the short wavelength region of the visible spectrum? c. If a substance absorbed the wavelengths from the short wavelength region of the visible spectrum, what would be its color? 3. Explain why roses are red and violets are blue." 4. a. Is the energy absorption associated with bands in an infrared spectrum of higher or lower energy than the lines appearing in a visible line spectrum? Explain. b. Identify the type of energy transition occurring in a molecule that causes a band to appear in an infrared spectrum c. Identify the type of energy transition occurring in an atom that causes a line to appear in a visible line spectrum. Dry Lab 3 171

Answer 1

Solution:

1) The experimental evidence for the quantized electronic energy states are observed by following experiment.

When an element is excited by heating or by passing electric current, the atoms of the element emit electromagnetic radiations of definite frequencies and hence definite wavelengths. The arrangement of these radiations in the order of increasing wavelength or decreasing frequencies is called emission spectrum of the element. These radiations in the spectrum are emitted due to energy changes in the atoms. The electromagnetic spectrum of the atoms is emitted when an electron jumps to the ground state from higher energy state. These assumptions generates the concepts of only quantized electronic energy states in atoms.