Atom

A. a land region on the earth’s surface covered by biological communities that group under the same climatic patterns like rainfall and temperature.

B. the descriptive and conceptual findings collected through questionnaires, interviews, or observation

C. a particle that consists of a nucleus of protons and neutrons surrounded by a cloud of electrons.

D. an element that remains unchanged or unaffected by other variables. It’s used as a benchmark or a point of comparison against which other test results are measured.