Meson octet. Diagram organising mesons into an octet according to their charge and strangeness. Particles along the same diagonal line share the same charge; positive (+1),neutral (0),or negative (-1). Particles along the same horizontal line share the same strangeness. Strangeness is a quantum property that is conserved in strong and electromagnetic interactions,between particles,but not in weak interactions. Mesons are made up of one quark and one antiquark. Particles with a strangeness of +1,such as the kaons (blue and red) in the top line,contain one strange antiquark. Particles with a strangeness of 0,such as the pion mesons (green) and eta meson (yellow) in the middle line,contain no strange quarks. Particles with a strangeness of -1,such as the antiparticle kaons (pink) in the bottom line,contain one strange quark |