Answer:
c.boron-11
Explanation:
The atomic mass of boron is 10.81 u.
And 10.81 u is a lot closer to 11u than it is to 10u, so there must be more of boron-11.
To convince you fully, we can also do a simple calculation to find the exact proportion of boron-11 using the following formula:
(10u)(x)+(11u)(1−x)100%=10.81u
Where u is the unit for atomic mass and x is the proportion of boron-10 out of the total boron abundance which is 100%.
Solving for x we get:
11u−ux=10.81u
0.19u=ux
x=0.19
1−x=0.81
And thus the abundance of boron-11 is roughly 81%.
The answer is D. To put it simply, all atom wished to become stable. The only way for that is to obtain an octet structure where the outermost shell would have 8 electrons, thus being full.
Answer:
Explanation:
The elements in Group I of the periodic table are called alkali metals. They are called alkali metals because they react with water to form alkali solutions. These metals are very reactive; hence they have to be stored under oil to protect them from corrosion by air and waterwaterwater
Answer:
<h2>117.94 moles</h2>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula

where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have

We have the final answer as
<h3>117.94 moles</h3>
Hope this helps you