Question

card 1 of 10
the smallest particle of an element that can exist.
the chemist knew she couldnt let any amount of that element into her experiment—not even a single atom.
write with this word

Explanation:

La definición dada ("the smallest particle of an element that can exist") corresponde a la definición de un átomo. El contexto de la oración ("not even a single atom") confirma que la palabra a usar es "atom".

Answer:

atom