Answer:
<em>The three gases, in the three identical containers, will all have the same number of molecules</em>
Explanation:
If these three gases (Helium He, Neon Ne, and Oxygen
) are all contained in separate identical containers with the same volume. And they are all stored at the same temperature, and pressure. Then, they'll all contain the same number of molecules. This is in line with Avogadro's law which states that "Equal volume of all gases, at the same temperature and pressure, have the same number of molecules."
Given the mass percentage of HCl solution = 15.00 %
This means that 15.00 g HCl is present in 100 g solution
Moles of HCl = 
Density of the solution = 1.075 g/mL
Calculating the volume of solution from density and mass:

Converting volume from mL to L:

Calculating the molarity of HCl solution from moles and volume:

True, the hardness of all materials in relative <span />
You can automatically rule out CH₄ since it has no lone pairs at all around the central atom. Water has 2. Ammonia is the only Lewis structure that contains one lone pair.
I’m not sure about the rest but 4 is families