Help fill in the gaps The cathode is _. The anode is_. The reaction at the cathode takes place: _. The electrons move _ and the ions in the electrolyte bridge move _ to the right (ZnSO4 solution) and _ to the left. The copper-zinc element stops working when the solution has run out of _ ions and / or the _ electrode.

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o