Answer:
63. 55 amu
Explanation:
Copper is known to exist in two different isotopes which are Cu-63 and Cu-65.
Cu-63 has an atomic mass of 62.93 amu and it has an abundance of 69.15%.
Similarly,
Cu-65 has an atomic mass of 64.93 amu and it has an abundance of 30.85%
Therefore, using the weighted average mass method, the atomic mass of copper is:
Atomic mass of copper = (0.6915*62.93) amu + (0.3085*64.93) amu = 43.52 amu + 20.03 amu = 63.55 amu
Thus, the atomic mass of copper (express in two decimal places) is 63.55 amu
Based on (repeated) experiments or observations, that describe or predict a range of natural phenomena. the answer is c (sorry if i’m incorrect)
Answer:
7.35 - 7.45
Explanation:
The pH scale ranges from 0 (strongly acidic) to 14 (strongly basic or alkaline). A pH of 7.0, in the middle of this scale, is neutral. Blood is normally slightly basic, with a normal pH range of about 7.35 to 7.45. Usually, the body maintains the pH of blood close to 7.40.
Hope this helps
Answer: R & D is the correct option.
Explanation:
Research and development department of a chemical industry requires individuals holding advanced degrees because :
- This will help the chemical industry to come up with new developments and advancements in preparation of the chemical products like :green methods to prepare certain chemicals which usually involves handling of toxic substances.
- Formulation and development of the new chemical substitutes
- Improvement of chemical product at microscopic level.
