If salt is compound is it pure element or compound

True or false when elements combine to form a mixture, the resulting chemical properties may be very different from those of the elements that make it.

How does an observation about an object differ from an inference about that object

Aswimming pool whose volume is 10 comma 000 gal contains water that is 0.01% chlorine. starting at tequals0, city water containing 0.003% chlorine is pumped into the pool at a rate of 5 gal/min. the pool water flows out at the same rate. what is the percentage of chlorine in the pool after 1 hour? when will the pool water be 0.006% chlorine?