Atomics are beings composed entirely of energy, which are likely related to the Pulse Bombus which exist on the planet Tallon IV and the basis used for the Harmony Class Drones that were created by the Luminoth of the planet Aether. Samus happened across these organisms in the Space Pirate Mother Ship and the ancient Wrecked Ship on the planet Zebes as well as in the GFS Valhalla and on the planet Bryyo.
Due to their energetic natures, strong energy blasts are adequate to destabilize their essences and cause them to rupture - this can easily be accomplished by striking them with charged beam technology. They are sustained by a core, which naturally generates a constant supply of electrical output. Once too much of this energy has been produced in abundance, the Atomic will discharge a section of its own body, which drops to the ground due to gravitational pull as it is no longer a living organism at this point. This small section may have a core of its own, however, as once it hits the ground it will detonate, although this is unlikely a purposefully malicious tactic and is more likely their way to continue survival, and could be considered an analogous act to a carbon-based organism's defecating. Despite this, however, they do show aggression when near sources of energy of an opposite polarization, to which they seem to immediately respond; the reasoning behind this is unknown at this time, although it seems likely to be some form of predatory habit.