Answer:
I think c biological processes
Compressions are regions of high pressure due to particles being close together
rarefactions are regions of low pressure due to particles being spread further apart
Longitudinal waves are often demonstrated by pushing and pulling a stretched slinky spring
The correct answer is ELECTRON. The part of an atom that is actively exchanged or shared in a chemical bond in the electron. Electron are negatively charged atoms.
The first one, "Production of hydronium ions."
