A) Salt, because salt can easily dissolve in water. Oil would not dissolve or evaporate in water (think of an oil spill - does that oil dissappear?). Aluminum foil would definitely not dissolve in water, so it is not soluble.
Answer:
The smallest unit of a compound is a molecule, which is made up of atoms held together by bonds.
Answer:
I think It's C
Explanation:
due to higher waves can get easy transfers and receive those signals for most things, such as radios, TVs, phone signals etc etc
Answer:
Approximately 
.
Explanation:
Note that both figures in the question come with four significant figures. Therefore, the answer should also be rounded to four significant figures. Intermediate results should have more significant figures than that.
<h3>Formula mass of strontium hydroxide</h3>
Look up the relative atomic mass of 
, 
, and 
on a modern periodic table. Keep at least four significant figures in each of these atomic mass data.
Calculate the formula mass of 
:
.
<h3>Number of moles of strontium hydroxide in the solution</h3>
means that each mole of formula units have a mass of 
.
The question states that there are 
of in this solution.
How many moles of formula units would that be?
.
<h3>Molarity of this strontium hydroxide solution</h3>
There are 
of formula units in this 
solution. Convert the unit of volume to liter:
.
The molarity of a solution measures its molar concentration. For this solution:
.
(Rounded to four significant figures.)
.
.
.