Answer: 5
Explanation: Arsenic, As, has 5 electrons in the 4th energy shell. 4s^2 and 4p^3. The electrons being added for the elements scandium through zinc are all going into the 3d orbital, in the 3rd energy shell. They don't count, since valence electrons are only those in the highest energy level, 4 in this case.
Answer: circle graph.
Justification:
A circle graph (also known as pie chart) is excellent to visualize the relative size of different sectors. Being the entire circle 100%, each sector will show the percent of each category.
In the given example, the circle will be divided in 3 different sectors, in which the size is proportional to the percent of each one.
In the given case::
<span>pH less than 8: 20%
</span><span>
</span><span> pH between 8 and 8.5: 50%,
</span><span>
</span><span>pH greater than 8.5: 30%
</span><span>
</span><span>
</span><span>So, a sector whose area is 20% will represent the first category, a sector whose area is 50% will represent the second category, and a sector whose area is 30% will represent the third category. The whole circle is 100%, this is the sum of the 3 categories is 100%.
</span>
Answer:
4054 kcal of heat is released during complete combustion of 354 g of octane.
Explanation:
Heat of combustion of 1 mol of octane is 
kcal
Molar mass of octane = 114.23 g/mol
We know, no. of moles = (mass)/(molar mass)
So, kcal of heat is released during complete combustion of 114.23 g of octane.
So, amount of heat is released during complete combustion of 354 g of octane = 
kcal = 4054 kcal
Hence 4054 kcal of heat is released during complete combustion of 354 g of octane.
