Answer:
(b)90mg/lb
Explanation:
The child can consume a maximum of 23 tablets with 80mg of acetaminophen, the total acetaminophen ingest is:

This value is for 8 hours, 8 hours is 1/3 of one day. This means that the dose that can be consumed in 24 hours is 3 times 1840mg.

To obtain the maximum allowable dose in mg per pound of body weight, divide this last value by the weight of the child in pounds.
Conversion of units: 

A control group is the comparison group that helps to "make sure your experiment works." A control group is separated from the rest of the experiment and nothing happens to it kinda like a controlled variable. Controlled variables are the variables in a experiment that remains the same for example a temperature, time, type of products, etc..
Hope this helps!
Answer: Option (b) is the correct answer.
Explanation:
According to the law of conservation of energy, it is known that energy can neither be created nor it can be destroyed.
But energy can be changed from one form to another.
Whereas entropy is the degree of randomness present within the molecules of a substance or object.
For example, gas molecules are able to move rapidly so, they have more entropy as compared to solid and liquid substances.
According to second law of thermodynamics, entropy of the system is always increasing.
Thus, we can conclude that "Conservation of energy" refers to the fact that energy cannot be created or destroyed but can be converted from one form to another.
Element Atomic Number Valency
Valency of Hydrogen 1 1
Valency of Helium 2 0
Valency of Lithium 3 1
Valency of Beryllium 4 2
Valency of Boron 5 3
Valency of Carbon 6 4
Valency of Nitrogen 7 3
Valency of Oxygen 8 2
Valency of Fluorine 9 1
Valency of Neon 10 0
Valency of Sodium (Na) 11 1
Valency of Magnesium (Mg) 12 2
Valency of Aluminium 13 3
Valency of Silicon 14 4
Valency of Phosphorus 15 3
Valency of Sulphur 16 2
Valency of Chlorine 17 1
Valency of Argon 18 0
Valency of Potassium (K) 19 1
Valency of Calcium 20 2
Valency of Scandium 21 3
Valency of Titanium 22 4
Valency of Vanadium 23 5,4
Valency of Chromium 24 2
Valency of Manganese 25 7, 4, 2
Valency of Iron (Fe) 26 2, 3
Valency of Cobalt 27 3, 2
Valency of Nickel 28 2
Valency of Copper (Cu) 29 2, 1
Valency of Zinc 30 2