Is helium more similar to argon or cesium?

Helium is more similar to argon than to cesium. Both helium and argon are noble gases, which means they have complete electron shells, making them chemically inert and unlikely to react with other elements. In contrast, cesium is an alkali metal with a different electron configuration and reactivity profile. Thus, helium shares more properties with argon due to their placement in the same group of the Periodic Table.