Why does each element have its own unique atomic line spectrum?

• A. Because elements have identical numbers of protons.
• B. Because the nucleus emits photons at random energies.
• C. Because each element has a unique arrangement of electrons and energy levels.
• D. Because all elements absorb the same wavelengths of light.

Answer: (C)

Verified step by step guidance

1. Understand that an atomic line spectrum is produced when electrons in an atom transition between different energy levels, emitting or absorbing photons of specific energies.
2. Recognize that each element has a unique number of protons, which determines the positive charge of the nucleus and influences the arrangement of electrons around it.
3. Know that the unique arrangement of electrons and the specific energy levels available in each element cause electrons to absorb or emit photons at characteristic wavelengths.
4. Realize that these unique energy differences between electron levels result in a distinct set of spectral lines for each element, known as its atomic line spectrum.
5. Therefore, the atomic line spectrum is unique to each element because of its unique electronic structure and energy level arrangement, not because of random photon emission or identical proton numbers.