Answer:
C. 114.8 u
Explanation:
The atomic mass of X is the <em>weighted average</em> of the atomic masses of its isotopes.
We multiply the atomic mass of each isotope by a number representing its relative importance (i.e., its percent of the total).
Set up a table for easy calculation
0.0429 × 112.90 u = 4.843 u
0.9571 × 114.90 u = <u>109.97 u
</u>
TOTAL = 114.8 u
Answer:
This stiffening process, called Rigor Mortis, has a roughly known time of occurrence and can therefore be used to estimate time of death. In general: If the body feels warm and no rigor is present, death occurred under 3 hours before. If the body feels warm and stiff, death occurred 3-8 hours earlier.

Thus 174 protons would make at most 6 copper atoms. However, it would take 174 extra electrons (29 per atom) and even more neutrons than that to construct neutral copper atoms with stable nuclei.
Answer: (2)3.0 mol
Explanation: 222.3g= 222.3/74= 3.0 mol
1mol Ca(OH)2 is 74g