The best answer is letter A.
The main factors that change the speed of enzymatic reactions are temperature, pH and substrate concentration (quantity). <span>There are enzymes that need other associated molecules to work. These molecules are called enzyme co-factors. They can be organic ions like mineral salts.</span>
Each water molecule consists of two atoms of the element hydrogen joined to one atom of the element oxygen. An interesting property of water is the ability of its molecules to “stick together.” This occurs because one side of each water molecule is slightly negative and the other side is slightly positive. The positive portion of a water molecule is attracted to the negative portion of an adjacent water molecule. As a result, water molecules are called polar molecules. They attract other water molecules like little magnets. It is most likely ionic bonding but between hydrogen and oxygen it is covalent.
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Chemical- it produces ammonia.
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