I diagram below shows what happens to water when an electric current is applied. From this diagram we see that hydrogen gas and oxygen gas are produced in this process which of the following correctly classifies this process. 1. This is a physical change because the chemical make up of the substance does not change.

2. This is a chemical change because the chemical make up of the substance does not change.

3. This is a physical change because new substances are formed with new properties.

4. This is a chemical change because new substances are formed with new properties.

hi my dude or dudette

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