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atom
Definition
An atom is the smallest unit of matter that can exist. It is made up of three tiny particles called protons, neutrons, and electrons. Protons and neutrons are found in the centre of the atom, called the nucleus. Electrons orbit the nucleus.
Atoms are very small. They are so small that you would need a microscope to see them. But even though they are small, atoms are very important. They are the building blocks of everything in the universe, including you and me!
How can the word be used?
The atom is the smallest unit of ordinary matter.
Different forms of the word
Noun: atom.
Adjective: atomic.
Adverb: atomistically.
Synonyms: molecule, particle, ion, element.
Antonyms: compound.
Etymology
The word "atom" comes from the Greek word átomos, which means "indivisible." The Greek word is made up of the prefix a, which means "not," and the noun tomos, which means "cut.".
Question
What can vary in an atom's nucleus?