A weak acid is an acid that does not fully dissociate in solution; that is, if the acid was represented by the general formula AH, then in aqueous solution a significant amount of undissolved AH still remains.
... Younghusband, (1863-1942), India and Tibet
Z
Zhang Qian[?] - spent 12 years starting in 138 BC exploring much of Central Asia for Emperor Han Wu Di[?]
Zheng He, ...