Answer:
B.111
Explanation:
Atomic mass = number of protons(or atomic number) + number of neutrons
186 = 75 + number of neutrons
number of neutrons = 186 -75 = 111
Answer:
<em>What is atmospheric pressure? -------> Atmospheric pressure is a force in an area pushed against a surface by the weight of the atmosphere of Earth, a layer of air.</em>
<em>Why does the atmosphere exert pressure? -------> Because gas particles in the air—like particles of all fluids—are constantly moving and bumping into things, so they exert pressure. </em>
<em>What is the value of atmospheric pressure at sea level, in newtons per square centimeter? -------> Atmospheric pressure at sea level is about 10 N/cm2 or 100 kPa or about 10 m of water or about 760 mm of mercury, but varies with the weather, and of course altitude.</em>
<em>I hope this helps and have a great day!</em>
Explanation:
The correct answer is D.
I hope that helped! c:
Answer: 17) d. 
18. c. The empirical formula of a compound can be twice the molecular formula.
Explanation:
Molecular formula is the chemical formula which depicts the actual number of atoms of each element present in the compound.
Empirical formula is the simplest chemical formula which depicts the whole number of atoms of each element present in the compound.
To calculate the molecular formula, we need to find the valency which is multiplied by each element to get the molecular formula.
The equation used to calculate the valency is:

The empirical mass can be calculated from empirical formula and molar mass must be known.
17. Thus the empirical formula of
should be 
18. The molecular formula will either be same as empirical formula or is a whole number multiple of empirical formula. Thus the empirical formula of a compound can never be twice the molecular formula.