The number of moles in monochloro pentaborane (9) 
is 0.37056.
We know that ,
Number of moles = Given mass/ Molar mass
Given mass of monochloro pentaborane (9) is 20.1 g
The molar mass of monochloro pentaborane (9) is
= 
= 
= 54.241
Thus number of moles = 20.1/54.241
= 0.37056
To know more about mole concept
brainly.com/question/20483253
#SPJ4
Answer: 121.7558 amu
Explanation:
Average atomic mass of the unknown element =
(Mass of isotope 1 x Relative Abundance of Isotope 1) + ( Mass of Isotope 2 x Relative Abundance of Isotope 2)
(120.9 x 0.5721) + (122.9 x 0.4279) = 69.16689 + 52.58891
Average mass of the unknown element = 121.7558 amu
Answer:
This is the correct answer please give me 5-star and likes
Explanation:
If nutrients are added to an ecosystem, then the composition of the plant community at different stages of succession will also change because different species take advantage of different soil conditions.
The chemical symbol for manganese is Mn.
Which of the following terms best describes the nucleus of a radioactive element?
C. Unstable
