hạ nguyên tử 
subatomic [ hạ ] : (1) summer; (2) to lower, let down (price, flag); to land (a plane)
[ nguyên ] : acting, holding a post temporarily; to be intact, unaltered, brand new, original; in full; all, whole, entire
[ tử ] : to die, decease
Most Common Compounds Set 1:
Most Common Compounds Set 2 :