Question

what is an atom and how big are atoms​

Answer 1

Explanation:

An atom is the smallest constituent unit of ordinary matter that constitutes a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small; typical sizes are around 100 picometers

(1×10−10 m, a ten-millionth of a millimeter, or 1/254,000,000 of an inch).

Answer 2

An atom a fundamental piece of matter. ... An atom itself is made up of three tiny kinds of particles called subatomic particles: Proton,Elclectron and Nuetron ..

Atoms are extremely small; typical sizes are around 100 picometers (1×10−10 m, a ten-millionth of a millimeter, or 1/254,000,000 of an inch).

Hope it helps :)