If a<span> student used 10 mL water instead of 30 mL for extraction of salt water from mixture, the extraction of salt will be lesser than compared to using 30 mL since less solute will dissolve in 10 mL.</span>
Answer:b.CaCl2
Explanation:
A compound is a substance resulting when two or more elements are are chemically bonded together either ionically or covalently in a fixed ratio.
From the given options we can see that the only compound there is CaCl2 which is an ionic compound in the fixed ratio of one calcium ion to two chloride ions.
Other options , Cu,Na and Nd are merely pure substance---Elements
It should be potential energy!!!