Crossword puzzle clue "elementary particle with no charge"

an uncharged subatomic particle with zero mass when at rest

a particle in the nucleus of an atom, which is without electrical charge and with approximately the same mass as a proton

(Greek) a Greek letter

an elementary particle

the name given to a hypothetical particle thought of as passing between quarks and so signifying the force that holds them together

one of a class of subatomic particles, including baryons and mesons