No, it is not possible for everything around you to be just one massive atom or a similar entity. Atoms are the basic building blocks of matter, and they consist of a nucleus, which contains protons and neutrons, surrounded by electrons. The arrangement and combination of atoms give rise to the vast variety of substances and objects we observe in the world.
The size of an atom is incredibly small, typically on the scale of picometers (trillionths of a meter). To have everything around you be just one massive atom would imply that all matter in the universe is condensed into a single entity, which is not consistent with our current understanding of physics and the structure of matter.
Furthermore, if such a scenario were to occur, the properties and interactions we observe in the world, such as chemical reactions, biological processes, and even our own existence, would not be possible. The diversity and complexity of the universe arise from the interactions and combinations of many different atoms and molecules.
In summary, while atoms are fundamental components of matter, they do not exist as singular massive entities encompassing everything around us. The physical world we perceive is the result of the arrangement and interactions of countless atoms and molecules.