Answer:
a chemical change is usually an irreversible chemical reaction. an example of this is rusting.
a physical change is usually visible while a chemical change isn't. also, a chemical change is irreversible while a physical change is.
Explanation:
<h2>Hello!</h2>
The answer is: 
<h2>Why?</h2>
First, we need to calculate the molecular weight of the acetone (CH3COCH3)
So,

Then,

Second, we need to calculate the mass of the acetone in the bottle
We need to remember that 
So,

Third, we need to calculate the number of moles:

Fourth, we need to calculate the number of atoms:
Remember, 
Therefore,

Have a nice day!
Answer:
It evaporates and moves into the air.
Explanation:
When water is left out for a while, it evaporates into the air! :)
Answer:
How many grams of CCL4 were formed? 116.9 g
How many grams of Cl2 reacted with the CH4? 243.8 g
Explanation:
First we need to know the molar mass for every element or compound in the reaction:

Now we proceed to calculate the amount of moles produced, per product:

To calculate the mass of chlorine we just need to make a mass balance:
