Answer:
25000 ppm
Explanation:
<em>Parts Per Million </em>is defined as the number of parts of a solute per one million parts of a solution.
ppm = (Weight of Solute / Weight of Solution) × 10⁶ ---(1)
Let us suppose that the air (solution) weights 100 grams, then 2.5 % of water vapors will have following mass,
Mass of Vapors g / 100 g × 100 = 2.5
Or,
Mass of Vapors = 2.5 × 100 / 100
Mass of Vapors = 2.5 g
Hence, mass of water vapors is 2.5 g.
Now, putting mass of water vapors and air in eq. 1,
ppm = (2.5 / 100) × 10⁶
ppm = 25000
Answer: Ionic formula will be 
.
Explanation: 
and 
ions will form a ionic compound. Ionic compounds have both metals and non-metals.
Here is a metal and is a non-metal.
The net charge on any compound must be 0.
So we need 2 phosphate ions to balance the charge on ions. Similarly we need 3 Magnesium ions to balance the charge on ions.
Criss-crossing the charges, we will get the formula as
Criss-crossing is shown in the image below.
Among the choices given, the correct answer is the first option. Substance X most likely is a crystal, and substance Y most likely is a liquid. Substance X having a fixed volume describes a crystal because crystals occupy a certain volume. Substance Y is a liquid because liquids can still be compressed further in order to attain a more packed <span>structure.</span>
