“Star cluster” is a generic way for astronomers to refer to a group of stars that formed from the same material and are gravitationally bound for at least some period of time. There are two major types of star clusters — globular clusters and open clusters — and they are actually quite different.
Hello this answer isn't copied like the other one.
The answer is 85 calories.
Hope this helps.
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Answer:
10.8amu
Explanation:
Given parameters:
Abundance of B - 10 = 20% = 0.2
Abundance of B - 11 = 80% = 0.8
Unknown:
Atomic mass of Boron = ?
Solution:
The atomic mass of Boron can be can be calculated using the expression below;
Atomic mass = (abundance of B - 10 x mass of isotope B - 10 ) +( abundance of B - 11 x mass of isotope B- 11)
Atomic mass = (0.2 x 10) + (0.8 x 11) = 2 + 8.8 = 10.8amu
