What are emission spectra? a. the photons emitted when an electron drops down an energy level. b. the change in thermal patterns when energy is released. c. the change in incandescence that occurs when thermal emission moves into the visible spectrum. d. the photons absorbed when an electron goes up an energy level.

A. The photons emitted when an electron drops down an energy level.

Explanation:

When a source emits electromagnetic radiation then the spectrum is called as emission spectrum. It is emitted during the process when an atom makes its transition of energy levels to ground state.

Ground state is the state where atom possesses the lowest energy. When an atom or molecule comes down from higher energy level to lower energy level, it emits the spectrum which is called as emission spectrum.

In meteorology, a  cloud  is an aerosol consisting of a visible mass of minute liquid droplets, frozen crystals, or other particles suspended in the atmosphere of a planetary body. nephology is the science of  clouds, which is undertaken in the  cloud  physics branch of meteorology.cirrus clouds  usually describe clouds high in the atmosphere that can include wispy clouds, typically with ice crystals. variations include cirrus, cirrocumulus and cirrostratus as defined by the cloud's position in the atmosphere.layered stratus clouds  have both flat tops and bases, and can appear as if they take up the whole sky, stretching from horizon to horizon. other combinations and variations include stratus, stratocumulus, nimbostratus and altostratus.cumulus clouds  often pile up in multiple layers of the atmosphere, representing clouds that develop vertically. cumulus clouds often look like pillars with anvil-type tops or columns of clouds stacked vertically. variations include cumulus, cumulus-congestus, cumulonimbus and altocumulus.

Well technically there are two correct answers b and d. but for you its probably b in general.good day sir/ma'am : ) (i know not gender)