Particle With No Charge, Found Alongside Protons
Puzzle 6 of Periodic Table Medium Pack
Question is: Particle With No Charge, Found Alongside Protons
and the answer is: NEUTRON
Word Meaning:
NEUTRON — (particle physics) A subatomic particle forming part of the nucleus of an atom and having no charge; it is a combination of an up quark and two down quarks.
Definitions from Wiktionary.