Question

_are called building blocks of matter (1) atoms (2) molecules (3) element​

Answer 1

ATOM

Well, the basic building blocks that make up matter are called atoms. Sometimes two or more atoms bond, or stick together, and form a molecule. ... Atoms consist of three particles: negatively charged electrons, positively charged protons and neutrons, which have a neutral charge.

Answer 2

$\bigstar \: \boxed{\sf{\color{red}{Atoms}}}$ are called the building blocks of matter.