Draw the following figure in your note book and find the perimeter or circumference show your solution.

1.) Triangle : s = 6cm ; P=

2.) Square : s = 7 cm ; P =

3.) Rectangle = W = 4cm , L = 8 cm ; P =

4.) Regular Heptagon : s = 3cm ; P =

5.) Circle : r = 12cm ; C =

Answers

Answer 1

1)Triangle : s = 6cm ; P= 18 cm

2.) Square : s = 7 cm ; P = 28 cm

3.) Rectangle = W = 4cm , L = 8 cm ; P = 24cm

4.) Regular Heptagon : s = 3cm ; P = 21 cm

5.) Circle : r = 12cm ; C = 24∏ cm.

What is circumference?

The circumference of a circle or ellipse in geometry is its perimeter. That is, if the circle were opened up and straightened out to a line segment, the circumference would be the length of the arc. The curve length around any closed figure is more often referred to as the perimeter.

Given that the length of each side of a triangle is 6 cm.

The perimeter of an equilateral triangle is 3a, where a is the length of the side of the equilateral triangle.

The perimeter of the triangle is 3 × 6 = 18 cm

The length of side of a square is 7 cm.

The perimeter of a square is 4a, where a is the length of the side of the square.

The perimeter of the square is 4 × 7 = 28 cm.

The length and breadth of a rectangle is W = 4 cm and L = 8 cm.

The perimeter of a rectangle is 2(L+ W)

The perimeter of the rectangle is = 2(8 + 4) = 2 × 12 =24 cm

The perimeter of Regular Heptagon is 7a, where a is the length of the side of the Regular Heptagon.

The perimeter of a Regular Heptagon is (7  × 3) = 21 cm

The perimeter of a circle with a radius r is 2∏r.

The perimeter of the circle is 2∏ × 12 = 24∏ cm.

To learn more about perimeter, click on the below link:

https://brainly.com/question/27148391

#SPJ1

Draw The Following Figure In Your Note Book And Find The Perimeter Or Circumference Show Your Solution.1.)

Related Questions

Select the correct answer. Consider the function f(x) = 2x and the function g(x) shown below. How will the graph of g(x) differ from the graph of f(x)? gx+2f(x)=2(2>x) A. The graph of g(x) is the graph of f(x) stretched horizontally by a factor of 2. B. The graph of g(x) is the graph of f(x) shifted to the right by a factor of 2. C. The graph of g(x) is the graph of f(x) stretched vertically by a factor of 2. D. The graph of g(x) is the graph of f(x) shifted up by a factor of 2.

Answers

Answer:

the answer to your question is A

Step-by-step explanation:

The graph of g(x) is the graph of f(x) stretched horizontally by a factor of 2.

Option A is correct.

What is a Function?

A mathematical phrase that establishes the link between an independent variable and a dependent variable (the dependent variable).

As per the given data:

We are given the function f(x) and the function g(x), also we are given the equation which related the functions f(x) and g(x).

We have to find the transformation that f(x) will undergo in order to get the graph of the function g(x).

From the given data:

f(x) = 2x

g(x) + 2f(x) = 2

∴ g(x) = 2 - 2f(x)

Now from the above equation we can clearly see that when 2 will be multiplied in f(x) its graph will be stretched horizontally by a factor of 2.

The graph of g(x) is the graph of f(x) stretched horizontally by a factor of 2.

Hence, The graph of g(x) is the graph of f(x) stretched horizontally by a factor of 2.

To learn more about Function, click:

brainly.com/question/12431044

#SPJ7

Which expression is equivalent to 5-3(x+2)?
A. -3x - 1
B. -3x+10
C. 2x + 4
D. 2x-6

Answers

The answer is A. -3x - 1
5-3(x+2)
5-3x-6
-3x+5-6
-3x-1

What is the multiplicative rate of change for the exponential function f(x)=2(5/2) in decimal form

Answers

The multiplicative rate of change for the exponential function is 0.4.

What is an exponential function?

The exponential function in mathematics is represented by the symbols f(x)=exp or ex. The word, unless otherwise stated, normally refers to the positive-valued function of a real variable, though it can be extended to complex numbers or adapted to other mathematical objects like matrices or Lie algebras.

In mathematics, an exponential function has the following form: f (x) = an x, where x is a variable and an is a fixed amount known as the function's base. The transcendental number e, or roughly 2.71828, is the most often encountered exponential-function base.

Given: Exponential function [tex]$f(x)=2\left(\frac{5}{2}\right)^{-x}$[/tex]

To find The multiplicative rate of change for the exponential function.

Solution :

The general form of the exponential function is [tex]$f(x)=a b^x$[/tex]

where $b$ is the rate of change of the function.

First we write the given function In proper form:

[tex]$$\begin{aligned}& f(x)=2\left(\frac{5}{2}\right)^{-x} \\& f(x)=2\left(\frac{2}{5}\right)^x\end{aligned}$$[/tex]

The rate of change is [tex]$f(x)=a b^x$[/tex]

Therefore, The multiplicative rate of change for the exponential function Is $0.4$

To learn more about exponential function refer to:

brainly.com/question/12940982

#SPJ1

-58 3 - 3 1 - 0
Solve.

Answers

Answer:

[tex]-9\frac{1}{4}[/tex]

Step-by-step explanation:

Rewrite our equation with parts separated

-5 - [tex]\frac{3}{4}[/tex] - 3 - [tex]\frac{1}{2}[/tex]

Solve the whole number parts

-5 - 3 = -8

Solving the fraction parts and Find the LCD

LCD = 4

[tex]-\frac{3}{4}[/tex] - [tex]\frac{2}{4}[/tex] = [tex]-\frac{5}{4}[/tex]

Simplify

[tex]-\frac{5}{4} = -1\frac{1}{4}[/tex]

Combine the whole and fraction parts

8 - 1 - [tex]\frac{1}{4}[/tex] = [tex]-9\frac{1}{4}[/tex]

Mark as Brainllest

1. In the diagram below which expression represents x, the measure of the exterior angle shown?

Answers

Answer:

a) a + b

Step-by-step explanation:

The value of the exterior angle x will be (a+b).

What is an exterior angle?

The angle made by the two lines of the figure which lie on the outside of the closed figure is called the exterior angle.

The exterior angle is the sum of the two opposite internal angles of any figure.

The exterior angle in the given figure will be equal to x = a+b the sum of the two opposite interior angles.

Therefore the value of the exterior angle x will be (a+b).

To know more about exterior angles follow

https://brainly.com/question/2546141

#SPJ2

Evaluate the expression Z/8, or z 8 for each of the following values for Z:

20) Z = 10.2

21) Z = 92

22) Z = 16.016

23) Z = 5 4/9

Evaluate each expression below if m = 32 and n = 150

24) m/16, or m by 16

25) 2N - 200

26) 3/4M -12

Answers

Answer:

1.275

11.5

2.002

0.68

2

0

12

Step-by-step explanation:

Evaluate Z/8 for each :

Z = 10.2 ; 10.2 / 8 = 1.275

Z = 92 ; 92/ 8 = 11.5

Z = 16.016 ; 16.016 / 8 = 2.002

Z = 5 4/9 ; (49 /9) ÷ 8 = 0.68

Evaluate each expression below if m = 32 and n = 150

m/16 ; 32 / 16 = 2

2N - 200 ; 2(150) - 300 = 300 - 300 = 0

3/4M -12 ; 3/4(32) - 12 = 24 - 12 = 12

PLEASE HELP! ASAP!!!!!!!!!!!!!!!!

Answers

Answer:

Area = 24 in.²

Step-by-step explanation:

Area of the parallelogram = base × height

base = 6 in.

height = h = ?

Use pythagorean theorem to find h

Thus:

h² = 5² + 3²

h² = 25 - 9

h² = 16

h = √16

h = 4 in.

Plug the values into the formula for area of parallelogram

Area = 6 × 4

Area = 24 in.²

Gabby assumed she could sell 45 boxes of cookies by Friday, but she only sold 26 boxes. What was Gabby's percent error? ​

Answers

Answer:

73.07%

Step-by-step explanation:

Given that,

Actual value of sold cookies = 26

Assumed value of sold cookies = 45

We need to find Gabby's percent error. The percentage error in a value is given by :

Error = ](Assumed value - Actual value)/Actual value]× 100

So,

[tex]\%=\dfrac{45-26}{26}\times 100\\\\=73.07\%[/tex]

So, Gabby's percent error is equal to 73.07%.

Answer: 73.1

Step-by-step explanation: Although the answer is 73.07 if you're in Acellus they want you to round to the nearest percent so the answer should be 73.1

what is Negative ninety two hundredths as number

Answers

is it -.92 ? not really getting the question

What is the volume of the following triangular prism?

Answers

Answer:

450 in²

Step-by-step explanation:

All we do is find the area of the triangle at the base and top then  multiply by the height so:

5×12=60

60÷2=30 is the area.

Now as I said we multiply with the height to get our answer:

30×15=450 in²

Answer:

A

Step-by-step explanation:

base area = (leg 1 x leg2)/2 = (12 x 5)/2 = 30 in^2

V = base area x height of the prism = 30 x 15 = 450 in^3

What is 10/83 simplified

Answers

Answer:

5/19

Step-by-step explanation:

10/83 is in its simplest form.

To identify if a fraction is further divisible or not, we find a common number that the numerator and denominator both can be divided by. In this case, 10/83 cannot be commonly divided any further than it is. Therefore, the fraction is in its simplest form.

Jacob runs 2652 yards in 15 minutes. Michael runs 7920ft in .375 hours. who will win the race?

Answers

Answer:

I think Jacob wins the race

Consider all five-digit numbers that can be created from the digits 0-9 0 - 9 where the first and last digits must be odd and no digit can repeat. What is the probability of choosing a random number that starts with 7 7 from this group? Enter a fraction or round your answer to 4 4 decimal places, if necessary.

Answers

There are a total of 5 digits that can be chosen for the first digit (1, 3, 5, 7, and 9), and 5 digits that can be chosen for the last digit (1, 3, 5, 7, and 9). Since no digits can repeat, the number of choices for the middle 3 digits is 9 * 8 * 7 = 504. Therefore, there are a total of 5 * 504 * 5 = 10,080 five-digit numbers that can be formed from the digits 0-9 where the first and last digits are odd and no digit can repeat.

Of these numbers, there are 504 numbers that start with 7, because there are 504 choices for the middle 3 digits and 1 choice for the first digit. Therefore, the probability of choosing a random number that starts with 7 from this group is 504 / 10,080 = 0.05, or approximately 5%.

Based on the experiment if a card is chosen 200 times how many times would you expect to pick a card without stripes?

Answers

The number of expected times to pick a card without strips is 130.

What is a percentage?

The percentage is calculated by dividing the required value by the total value and multiplying by 100.

Example:

Required percentage value = a

total value = b

Percentage = a/b x 100

Example:

50% = 50/100 = 1/2

25% = 25/100 = 1/4

20% = 20/100 = 1/5

10% = 10/100 = 1/10

We have,

The percentage of stripes from the 120 times.

= 42/120 x 100

= 35%

Now,

Based on this experiment,

The number of strip cards out of 200 times.

= 35% of 200

= 35/100 x 200

= 35 x 2

= 70

The number of times to pick a card without strips.

= 200 - 70

= 130

Thus,

The expected number of times to pick a card without stripes is 130.

Learn more about percentages here:

https://brainly.com/question/11403063

#SPJ1

The complete question is given below.

find the slope for 1-6

Answers

Answer:

1) 10/3

2) -1./3

3) -2/5

4) 1

5) undefined

6) 0

Step-by-step explanation:

Find two easy to read points. Go from one point to the other by going vertically first then horizontally. Moving up is positive and down is negative. Moving right is positive and left is negative.

slope = rise/run = (difference in y)/(difference in x)

1) slope = 10/3

2) slope = -1/3

3) slope = -2/5

4) slope = 1/1 = 1

5) slope = undefined (The slope of a vertical line is undefined.)

6) slope = 0 (The slope of a horizontal line is 0.)

Select each expression that is equivalent to 4n+12

A. 16n
B. 2n+6+2n+6
C. 2(2n+4)+2
D. 4(n+3)
E. 3(n+4)+n
F. n+n+n+n+12

Answers

Answer:

B D E F

Step-by-step explanation:

The answers are B, D, E, F

What is the difference In -4-(-7)

Answers

Answer:

Step-by-step explanation:The Apple iPhone 7 has a 4.7-inch size display, while the iPhone 7 Plus has a 5.5-inch display. The standard iPhone 7 has a 1334 x 750 pixel resolution, while the Plus has a Full HD resolution meaning their pixel densities are 326ppi and 401ppi, respectively.

I WILL GIVE U BRAINLIEST AND THANKS AND 5 STARS
-------------------------------------------------------------------------------------
please help this is very important

Answers

Answer:

C

Step-by-step explanation:

Answer:

Area of a rectangle=LxW

There's 2 rec's there

For the first

A= 1/3.s

For the second

L=12

W= 1/3

A = 1/3 . ( 12)

Total Area = 1/3.s + 1/3(12)

Now This can also be simplified by factorization

Total Area = 1/3(s+12)

We factored out 1/3 from both sides.

The question asked to select ALL THE EXPRESSION That represents the total area.

SO OPTION C and E

A pipe has 9/16" that is threaded, but you need to trim 4/32" off of the threaded part. How long will the threaded be after the trim? a. 17/32, b. 7/8, c. 7/16, d/ 15/32

Answers

To find the answer, we can begin by converting 9/16 to a denominator of 32. This can be done by multiplying everything by 2:

9 • 2 = 18
16 • 2 = 32

Our new fraction is 18/32. Now to subtract:

18/32 - 4/32 = 14/32

With our new fraction, we can divide the numerator and denominator by 2 to find that:

18/32 - 4/32 = 7/16

Hence, our final difference is option C.

An international company has 22400 employees in one country. If this represents 18.3 of the company's employees, how many employees does it have in total? Round your answer to the nearest whole number.

Answers

The total number of employees that this company would be said to have is given as 122424

How to solve for the number of employees

How to solve for the number of employees in the company

We know that the number of employees in one country is 22400, and that this represents 18.3% of the company's employees in total.

We can use this information to set up a proportion to find the total number of employees in the company.

Employees in one country / Total employees = 18.3 / 100

22400 / X = 18.3/100

To find the total number of employees, we can cross-multiply and divide:

X = (22400 * 100) / 18.3

X = 122424

So the company has a total of 122424 employees.

Read more on proportions here: https://brainly.com/question/19994681

#SPJ1

Abi is carrying 3 gallons of milk. Each gallon of milk weighs 8.6 pounds. Abi wants to know the total weight of milk he is carrying.
Abi draws the area model below to find the product of 3 and 8.6.
8
0.6
3
3 x 8 = ?
3 x 0.6 = ?
What is the total weight of the milk he is carrying?
Use the number pad to enter your answer in the box.

Answers

Answer:

25.8 pounds

Step-by-step explanation:

3 x 8.6 = 25.8

2//2/2/3/2/2//3/3/3//3/3/4/5/5​

Answers

Answer:  

can u be more specific so i can properly help u  

Explanation:  

pls explain and i will edit my answer  

What do you need help with.

An 8 ¼ -inch circular power saw blade rotates at 4400 revolutions per minute. (Round your answers to two decimal places.)
(a) Find the angular speed of the saw blade in radians per minute. ___________________







(b) Find the linear speed (in feet per minute) of the saw teeth as they contact the wood
being cut.
___________________

Answers

a) The angular speed of the saw blade in radians per minute is;

460.77 radians per minute.

b) The linear speed (in feet per minute) of the saw teeth as they contact the wood being cut is; 7.46 * 10⁻⁴ ft/min

How to find angular and linear speed?

a) Angular speed is defined as the speed of the object in rotational motion

The formula of the angular speed is; ω = θ / t

where;

ω is the angular speed

θ is the angular rotation

t is the time taken.

We are given;

In one revolution, the angle made is 2π radian.

In 4400 revolutions = 2π * 4400 radian

= 8800π radians

We know that ,

1 hour = 60 minute.

Thus;

Angular speed = 8800π/60

= 460.77 radians per minute

b) The relationship between the linear speed and angular speed in a uniform circular motion is given by the formula;

s = rω

where;

s is the linear speed

r is the radius

ω is the angular speed.

radius = 8 ¼ -inch/2 = 33/8 inches

Conversion from inches to feet gives;

33/8 inches = 0.34375 ft

Thus;

s =  0.34375/460.77

s = 7.46 * 10⁻⁴ ft/min

Read more about Angular and linear speed at; https://brainly.com/question/29345009

#SPJ1

This function describes the time, t(d), in seconds, an object takes to hit the ground after falling d feet.
t (d) =sqrt{d/16}
How long will it take for an object to fall 1,600 feet?
A. 4 seconds
B. 10 seconds
C. 100 seconds
D. 160 seconds

Answers

Answer:

help me plzz

Step-by-step explanation:

The velocity of a particle moving along the x-axis is v(t) = cos(2t), with t measured in minutes and v(t) measured in feet per minute. To the nearest foot find the total distance travelled by the particle from t = 0 to t = π minutes

How many sixteenths are there in 3/8 ?

Answers

6 sixteenths are in 3/8

Answer:

6 sixteenths 6/16

Step-by-step explanation:

8 x 2 = 16

3 x 2 = 6

mila was baking cookies this weekend. she took 3 over 20 of the cookies to school on monday. and she gave 7 over 20 of the cookies to her neigbor. how much of the cookies did she gave away?
A
G
O
N
S

A

Answers

Answer:

Step-by-step explanation:

As she is baking cookies = 3/20

she egave it to her neigbour = 7/20

Remaining = ?

R = 3/20 -7/20 = -1/5

cuál es el resultado de |-15| x (-5)​

Answers

Answer:

[tex]\frac{15}{x^5}[/tex]

Step-by-step explanation:

[tex]\left|-15\right|x^{-5}[/tex]

Step 1: Apply exponent rule: [tex]\:a^{-b}=\frac{1}{a^b}[/tex]

[tex]=\left|-15\right|\frac{1}{x^5}[/tex]

Step 2: Multiply fractions: [tex]a\cdot \frac{b}{c}=\frac{a\:\cdot \:b}{c}[/tex]

[tex]=\frac{1\cdot \left|-15\right|}{x^5}[/tex]

Step 3: Simplify

[tex]=\frac{15}{x^5}[/tex]

The result is [tex]=\frac{15}{x^5}[/tex]

Spanish/Espanól

Respuesta:

[tex]\frac{15}{x^5}[/tex]

Explicación paso a paso:

[tex]\left|-15\right|x^{-5}[/tex]

Paso 1: aplique la regla del exponente: [tex]\:a^{-b}=\frac{1}{a^b}[/tex]

[tex]=\left|-15\right|\frac{1}{x^5}[/tex]

Paso 2: multiplica fracciones: [tex]a\cdot \frac{b}{c}=\frac{a\:\cdot \:b}{c}[/tex]

[tex]=\frac{1\cdot \left|-15\right|}{x^5}[/tex]

Paso 3: simplifica

[tex]=\frac{15}{x^5}[/tex]

El resultado es [tex]=\frac{15}{x^5}[/tex]

What is the conditional frequency of a student who rides the bus being late to class first period?

Answers

Answer:

1/5

Step-by-step explanation:

The Constraint is ; those who rode the bus, hence it is conditional because we aren't focused on students, only students who rode the bus.

Now we want the frequency of those who were late Given that they rode the bus : for these we have 3 students

Total number of students who rode the bus , total possible outcome = 15

Hence, the conditional frequency = (number who rode bus and were late / otal number who rode the bus)

Hence, we have ; 3 / 15 = 1 / 5

What do the properties of polynomial addition mean? Complete each statement.
The closure property states that the sum of two polynomials is a
The commutative property states that changing the order of two or more terms
~ the value of the sum.
The associative property states that the way in which two or more terms are grouped in a sum
the value.

Answers

The Complete statement are:

The closure property states that the sum of two polynomials is a polynomial.

The commutative property states that changing the order of two or more terms does not change the value of the sum.

The associative property states that the way in which two or more terms are grouped in a sum does not change the value of the sum.

What is the properties of polynomial addition about?

The properties of polynomial addition include closure, commutativity, and associativity.

These properties of polynomial addition make it easy to perform arithmetic operations with polynomials because they have predictable results and the order in which the polynomials are grouped or ordered does not change the final result.

Therefore, In simple terms, closure property ensures that the sum of two polynomials is also a polynomial, commutative property ensures that the order of the polynomials does not change the sum and the associative property ensures that the grouping of the polynomials does not change the sum.

Learn more about  closure property  from

https://brainly.com/question/19340450

#SPJ1

Answer:

Step-by-step explanation:

Kevin hopes to earn a college basketball scholarship. To improve his shooting skills, Kevin shoots 50 baskets / day. If Kevin shoots 50 baskets every day for 60 days, how many shots will Kevin take?

Answers

The answer is 3000 shots
Other Questions
Driving around the parks that encircle Washington, he solicited customers with a simple pitch: early in themorning, he would deliver some bagels and a cash basket to company's snack room; he would return beforelunch topick up the money and the leftovers. It was an honor-system commerce scheme, and it worked. Within dfew years, Feldman was delivering 8,400 bagels a week to 140 companies and earning as much as he had evermade as a research analyst. He had thrown off the shackles of cubicle life and made himself happy.The authors prove Feldman's success by describing _____ Why do you suppose that Hinton has Ponyboy talk about the greaser's criminal behaviors with an accepting tone? hey guys its my final! mind helping? 30 points! will mark the brainiest 3 increased by anumber times 2 Does a ball rolling down a ramp have constant acceleration? Why do all humans have similar features? O They have the same number and kinds of chromosomes. Their genes do not allow for any variation. O They have identical alleles. O They have different alleles. The government doesn't need to penalize people for notwearing a seatbelt because they're already penalizedenough when they get into an accident.The sentence above would most likely be used in an essay with which ofthese text structures?A. DescriptiveB. ArgumentativeC. Compare and contrastD. Cause and effectSUBMIT 1. How did the speaker's memories of the valley affect him during the past five years? A They tormented him. B They restored his spirit. They made him resent city life. D They caused him to avoid nature . Slide #1. Geography. Include the location of your biome by including a relevant map to show where the biome is located. You may circle the locations on the map if necessary or use arrows to point them out. (Remember to cite the source of your map!). Please also list out the country or countries where your biome is located. (In the case of the US, please list the states where your biome is located.)Slide #2. Annual Precipitation and Summer/Winter Temperatures. Include the average precipitation for your biome (indicate whether it is mostly rain, snow, etc.) and also what the average high/low temperatures are during both the summer and winter. Include any additional information about weather that is important for your biome. Use clipart or actual photos to make your slide more attractive.Slide #3, 4 and 5. Animals. Identify 3 different animal populations that are present in your biome. For each animal population, include 3 interesting facts about the animals (these may include adaptations to the biome, population trends, etc.). Include pictures of each type of animal. 1. Key Ideas and Details: How does Mathabane hint that his life is about to change on the day in which this scene takes place? Name two events from the text and explain how you know they signal something unusual is going to happen.2. Key Ideas and Details: What details from Mathabanes life explain why he is so determined not to go to school? 3. Craft and Structure: Mathabane chooses to use mostly indirect dialogue in the beginning of the story and mostly direct dialogue at the end. What effect do his choices have on the pacing of the story? Why do you think he makes these choices? 4. Craft and Structure: Describe how the author uses active verbs to develop his characters in the part of the scene after the narrator is told he will be going to school.5. Look back through the text and find examples of direct and indirect dialogue. List and label them in the chart that follows. Practice the two methods of writing dialogue by paraphrasing the examples of direct dialogue and rewriting indirect dialogue as direct dialogue, being sure to punctuate it correctly. The value of y varies directly with x. If x = 3, then y = 4. What is the value of x when y = 120 ? A health insurance company wants the opportunity to cover the accounts of all county employees. In order to land this account, they must get the approval of the county board of directors. The board members mention that they are taking some time off to prepare for the holidays and say that the company might stay on their minds if they were given some holiday spending cash. What kind of crime is this an example of Choose the best answer to complete the sentence.Necesito _____ el programa en mi computadora.1.) reiniciar2.) instalar3.) imprimir4.) escanear Isabella has already baked 4 pies, and she can bake 2 pies with each additional cup of sugar she buys. Write an equation that shows the relationship between the additional cups of sugar x and the number of pies y. 20 PTS WILL GIVE BRAINLIESTA cactus can be found in the desert. Provide two examples of abiotic factors that ecologists would study when examining cactuses. what are these in englishel armarioel cartella camael espejola cmodala lmparalas cortinasel despertadorla mesitalas ropaslos zapatosla puertalos animales de pelucheel escritorio In third-degree AV block, there is no electrical communication between the atria and ventricles, so there is no relationship between the P waves and the _________. Which programming problem stems from multiple threads not executing in a predictable, sequential pattern What is the measure, in degrees, of ZA? why is oxygen more electronegative than nitrogen