No mountains in the world are increasing in size
Answer:

Explanation:
When percentage composition is given, and asked for the empirical formula, it is simplest to assume 100 g of material. Thus,
Mass C = 40.92 g. Moles C = 40.92 g x 1 mole/12 g = 3.41 moles C
Mass H = 4.58 g. Moles H = 4.58 g x 1 mole/1.0 g = 4.58 moles H
Mass O = 54.50 g. Moles O = 54.50 g x 1 mole/16 g = 3.41 moles O
Now, we want to get the moles into whole numbers, so we begin by dividing all by the smallest, i.e. divide all values by 3.41.
Moles C = 3.41/3.41 = 1
Moles H = 4.58/3.41 = 1.34
Moles O = 3.41/3.41 = 1
Now, in order to get 1.34 to be a whole number we multiply it (and all others) by 3
Moles C = 1x3 = 3
Moles H = 1.34x3 = 4
Moles O = 1x3 = 3
Empirical Formula 
<span>By definition, summer is the portion of the year in which the hemisphere is tilted toward the sun, so that sunlight strikes the surface more directly. When it is summer in the northern hemisphere, it is winter in the southern hemisphere, and vice versa</span>
D. Air molecules touch the warm ground, heating them up
The answer is yes. A chemical change occurred.
Chemical change is defined as the rearrangement or alteration in the of atoms in one or more substance which result in the formation of a new substance.
In the above, you mixed two clear liquids and the result was a new substance which is a colored solid precipitate at the bottom of the beaker.
This means that changes in the atoms of the two clear liquids occurred leading to the formation of this new solid substance.
This means that chemical change has occurred.
Hope this helps :)