The ancient Greeks used to believe that there were four elements: water, air, earth, and fire. A student is trying to create a dichotomous key that will identify fire out of the four elements. The key the student makes can be seen below.
Is visible to the naked eye
Y
Is cool to the touch
Air
is a liquid
Water
IN
Earth
Fire
What mistake did the student make?
Fire and water are switched.
Earth and air are switched.
O Earth is a liquid, so it is in the wrong position.
Air is visible to naked eye, so it is in the wrong position.

e

explanation:

solute : a solute is a substance that is dissolved in another substance is known as a solvent. it is mixed with a special mixture know as homogeneous mixture.

solvent: a solvent is a substance that dissolved a solute, which results in a solution is known as solvent.

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