Describe how is thermometer uses the thermal expansion of a material to measure temperature?

The red liquid in a thermometer tells you what temperature the thermometer has. So when you dip that thermometer in a warm substance, the red liquid (generally mercury) rises because the warmth makes the liquid expand or jump. The vice versa occurs with a cold substance. That's why you see the liquid going down when you put the thermometer on an ice cube.

Explanation:

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