A metalloid is a type of chemical element which has a preponderance of properties in between, or that are a mixture of, those of metals and nonmetals.
Answer:
0.02 tons of NO produced when 4 tons of coal is burned
Explanation:
From the given,
Chemical formula of coal = 
Molecular mass of coal = 
Let’s calculate the mass of nitrogen in coal


Amount of coal burnt = 4tons
Amount of NO produced by burning 4tons = 
This nitrogen is converted into NO by reacting with atmospheric oxygen.
Answer: Neutral Value
Explanation: pH of the blood is maintained at 7.0 to 7.5that is neutral value.
This is because if the pH of the is lower than the maintained value then it will become acidic .
Acidic pH can cause the medical urgency known as acidosis leading to vomiting, diarrhea etc.
If the pH becomes higher, then the blood will become basic in nature and it can also leas to the death of the person.
That is why the pH of the blood is maintianed at neutral value of 7.0 to 7.5