How can you improve the percent yield of copper in this lab? check all possible strategies that will you do so.

ans)measure reactants precisely.

ans)stir to the reaction take place.

chill the reactants before combining them.

ans)wait patiently until the reaction completes.

ans)make sure to recover as much copper as possible.

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? a. the balloons both rise. the cold balloon is larger than the warm balloon. b. the balloons rise at the same rate. both balloons are the same size. c. the warm balloon expands and rises. the cold balloon shrinks and sinks. d. the cold balloon expands and rises. the warm balloon shrinks and sinks.

Why do cells appear different in distilled water than they do in 10% salt water?

Scientists have developed an explanation of a phenomenon from several verified hypotheses. the explanation has been confirmed through numerous experimental tests. which option best describes this explanation? a. scientific lawb. research questionc. hypothesisd. scientific theory