Spectra: Emission and Absorption Concepts

The video tutorial explains different types of spectra, including continuous, emission, absorption, line, and band spectra. Continuous spectrum results from the dispersion of white light, producing a seamless range of colors. Emission and absorption spectra are related to the behavior of gases or vapors, with emission spectra showing bright lines on a dark background and absorption spectra showing dark lines on a bright background. Line spectra are characteristic of atoms, while band spectra are associated with molecules, such as the H2 molecule, and involve closely spaced lines due to atomic vibrations and rotations.

What is the main characteristic of a continuous spectrum?

• It has gaps between colors.

• It consists of bright lines on a dark background.

• It is only produced by gases.

• It shows a seamless spread of colors.

Which of the following sources can produce a continuous spectrum?

• An incandescent filament lamp

• A fluorescent light

• A gas at low temperature

• A laser

What is the main difference between emission and absorption spectra?

• Absorption spectra are only produced by solids.

• Emission spectra have bright lines on a dark background.

• Absorption spectra have bright lines on a dark background.

• Emission spectra have dark lines on a bright background.

What causes the bright lines in an emission spectrum?

• Absorption of energy by electrons

• Emission of energy by electrons

• Vibration of molecules

• Rotation of atoms

What is a line spectrum also known as?

• Molecular spectrum

• Band spectrum

• Continuous spectrum

• Atomic spectrum

Which element is commonly associated with a line spectrum?

• Hydrogen

• Oxygen

• Nitrogen

• Carbon

What causes the distinct lines in a line spectrum?

• Absorption of light by gases

• Excitation and de-excitation of electrons

• Rotation of atoms

• Vibration of molecules

What is a band spectrum characteristic of?

• Solids

• Molecules

• Atoms

• Gases

What causes the bands in a band spectrum?

• Excitation of electrons

• Vibration and rotation of atoms

• Absorption of energy

• Emission of light

Which molecule is given as an example of a band spectrum?

• CO2

• H2

• N2

• O2