Answer:
compound
Explanation:
A molecule is the smallest particle in a chemical element or compound that has the chemical properties of that element or compound. Molecules are made up of atoms that are held together by chemical bonds. These bonds form as a result of the sharing or exchange of electrons among atoms.
b. Na2HPO4 + NaH2PO4.
A <em>buffer </em>is a solution of a weak acid and its conjugate base. The weak acid is H2PO4^(-) and its conjugate base is HPO4^(2-).
All the other options are incorrect because they consist of only a single component.
I think it's Sodium Sulfide, because Na2S contains one Sodium and two Sulfur. Plus Sulfide<span> is used to describe any of three types of chemical compounds that contain sulfur.</span>
<span>True. Acid rain is formed when compounds released during the burning of fossil fuels, such as sulfur dioxide and nitrous oxide, dissolve in water droplets in clouds. These then fall as rain as part of the water cycle. While some rain is naturally acidic, human activities, like burning fossil fuels, have made it worse.</span>
Answer: The mass of air present in the room is 37.068 kg
Explanation : Given,
Length of the room = 10.0 ft
Breadth of the room = 11.0 ft
Height of the room = 10.0 ft
To calculate the volume of the room by using the formula of volume of cuboid, we use the equation:

where,
V = volume of the room
l = length of the room
b = breadth of the room
h = height of of the room
Putting values in above equation, we get:

Conversion used : 
Now we have to calculate the mass of air in the room.



Conversion used : (1 kg = 1000 g)
Therefore, the mass of air present in the room is 37.068 kg