A regular pentagon may be divided into 5 congruent triangles.
If the side of the pentagon is 6 feet, each base of the triangles will be 6 feet.
If the distance from the center to a vertex is 6 feet, all the sides of the triangles will 6 feet.
So there are 5 congruent, equilateral triangles each with side equal to 6 feet.
The area one of those triangles is calculateb by:
base * height / 2
height ^2 = (side length) ^2 - (side length /2)^2 = 6^2 - 3^2 = 36 - 9 = 27
=> height = √(27) ≈ 5.2 feet
And, using area = base * height / 2 ,
area of a triangle = 6 feet * 5.2 feet / 2 = 15.6 feet^2
And the area of the entire pentagon equals 5 triangles ≈ 5 * 15.6 feet^2 = 78 feet^2
Answer: 78 feet^2
<u>Answer:</u> In the reaction, magnesium atoms lose electrons.
<u>Explanation:</u>
An ionic compound is defined as the compound which is formed when electron gets transferred from one atom to another atom. These are usually formed when a metal reacts with a non-metal or a metal reacts with a polyatomic ion or a reaction between two polyatomic ions takes place.
Magnesium is 12th element of the periodic table having electronic configuration of 
This element will loose 2 electrons to form 
ion
Chlorine is 17th element of the periodic table having electronic configuration of 
This element will gain 1 electron to form 
ion
By criss-cross method, the oxidation state of the ions gets exchanged and they form the subscripts of the other ions. This results in the formation of a neutral compound.
The ionic compound formed is 
Hence, in the reaction, magnesium atoms lose electrons.
The ph of a saturated solution of Ca(OH)2 is 12.35
CALCULATION:
For the reaction
Ca(OH)2 → Ca2+ + 2OH-
we will use the Ksp expression to solve for the concentration [OH-] and then use the acid base concepts to get the pH:
Ksp = [Ca2+][OH-]^2
The listed Ksp value is 5.5 x 10^-6. Substituting this to the Ksp expression, we have
Ksp = 5.5 x 10^-6 = (s) (2s)^2 = 4s^3
s3 = 5.5x10^-6 / 4
Taking the cube root, we now have
s = cube root of (5.5x10^-6 / 4)s
= 0.01112
We know that the value of [OH-] is actually equal to 2s:
[OH-] = 2s = 2 * 0.01112 = 0.02224 M
We can now calculate for pOH:
pOH = - log [OH-]
= -log(0.02224)
= 1.65
Therefore, the pH is
pH = 14 - pOH
= 14 - 1.65
= 12.35
