The emission of a continuous range of frequencies of electromagnetic radiation?

• A. Continuous spectrum
• B. Line-emission spectrum
• C. Orbital
• D. Heisenberg uncertainty principle

Answer: (A)

This item tests understanding of what a continuous spectrum is. A continuous spectrum appears when a source emits photons across a broad range of energies, such as a hot solid or dense gas, where many possible energy transitions and thermal motions fill in all the wavelengths. The result is a smooth continuum with no gaps. This differs from a line-emission spectrum, where only specific wavelengths appear because atoms or molecules emit photons only during particular, discrete energy transitions. The Heisenberg uncertainty principle is a fundamental quantum idea, but it doesn’t describe the appearance of the spectrum, and orbital refers to where electrons reside and their energy levels, not the presence or absence of continuous spectral features.