mixture is 混和物
A mixture is formed when mixing different materials which may be all sorts of things
Milk, Salt Water, oil, and soup are all mixture. When we talk about mixture, we think of it as something contrast to pure substance.
A compound is 化合物, according to Merriam Webster's on-line dictionary,
It is: something formed by a union of elements or parts; especially : a distinct substance formed by chemical union of two or more ingredients in definite proportion by weight
A compound is usually formed by the force of chemmical bonds between different chemical elements..
CO2(Carbon and Oxygen), NaCl(Sodium and Chlorin), NaHCO3....are all compounds, not mixture. Conmparing to mixtures, they're pure substances.