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3 years ago

On a time quizzed please help

Mathematics

2 answers:

zhuklara [117]3 years ago

4 0

Answer:

Element Valence electrons

Nitrogen 5

Silicon 4

Oxygen 6

Magnesium 2

Explanation :

Valence electrons : Valence electrons are the electrons which is present on the outermost shell of the electron.

The given element is nitrogen that belongs to group 15 and the atomic number 7.

The number of electrons present on nitrogen element are 7.

The electronic configuration of nitrogen element is,

The number of valence electrons present on nitrogen element are, 5.

The given element is silicon that belongs to group 14 and the atomic number 14.

The number of electrons present on silicon element are 14.

The electronic configuration of silicon element is,

The number of valence electrons present on silicon element are, 4.

The given element is oxygen that belongs to group 16 and the atomic number 8.

The number of electrons present on oxygen element are 8.

The electronic configuration of oxygen element is,

The number of valence electrons present on oxygen element are, 6.

The given element is magnesium that belongs to group 2 and the atomic number 12.

The number of electrons present on magnesium element are 12.

The electronic configuration of magnesium element is,

The number of valence electrons present on magnesium element are, 2.

Step-by-step explanation:

shutvik [7]3 years ago

3 0

Answer:

Nitrogen has 5, Silicon has 4, Oxygen has 6, Magnesium has 2

Step-by-step explanation:

You will need a periodic table to figure this out. You will notice that at the top of each group that there are numbers from 1 to 18. The last number of each group is the valence electrons. This doesn't work for transition metals though. So for example if you look at where Nitrogen is located, it is underneath the 15 so there are 5 valence electrons. Valence Electrons is the most outer part of the electrons. There can only be a total of 8 electrons in each ring. Silicon is located in the 14 row (group) so there are 4 valence electrons. Oxygen is in the 16th so there are 6. And magnesium is in the 2nd group, so there are 2 valence electrons. This only works for groups 1, 2, 13, 14, 15, 16, 17, and 18. The transition metals in the middle do not go with this rule. Hope this helped out.

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What is the length of the side of a right triangle that has a side length of 8 in. and a hypotenuse that measures 17 in.?

lozanna [386]

It would be: 17² = 8² + b²
b² = 289 - 64
b = √225
b = 15

In short, Your Answer would be Option C

Hope this helps!

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3 years ago

Which statements about countries with lower GDP and lowest HDI scores are accurate? Check all that apply

yKpoI14uk [10]

Answer:The countries with lower GDP are the same as those with the lowest HDI.

U GDP is a solid indicator of what a country's HDI will be.

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Step-by-step explanation:

Which statements about countries with lower GDP and lowest HDI scores are accurate?

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3 years ago

Read 2 more answers

Which correlation coefficient represents the strongest downward trend in a data set? -0.83 -0.23 0.12 0.92

klasskru [66]

Answer: -0.83

Step-by-step explanation:

A correlation coefficient(r) is used to determine the strength and direction of the relationship between two variables.

-1 ≤ r ≤1

For downward trend r is negative.

For strong correlation r should be closer to 1 or -1.

From the given correlation coefficients -0.83 is both negative and closer to -1.

Hence, a correlation coefficient represents the strongest downward trend in a data set = -0.83

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3 years ago

If tanA+cotA=2 then find the value of cosA

aniked [119]

Answer:

cos A=

$\frac{1}{ \sqrt{2} }$

Step-by-step explanation:

We know,

cotA=

$\frac{1}{ \tan(a) }$

Substituting the value of cot A in the given equation, we get

$\tan( a) + \frac{1}{ \tan(a) } = 2$

$\frac{{ \tan }^{2} a + 1}{ \: \tan(a) } = 2$

${ \tan }^{2 \: } a \: + 1 = 2 tan \: a$

${ \tan }^{2} a - 2 \tan \: a + 1 = 0$

$( \tan \: a - 1) {}^{2 } = 0$

$\tan \: a - 1 = \sqrt{0}$

$\tan \: a = 1$

$\tan \: a \: = \tan \: 45$

$a = 45$

$\cos \: a = \cos \: 45$

$\cos \: a = \frac{1}{ \sqrt{2} }$

4 0

3 years ago

Four functions are given below. Either the function is defined explicitly, or the entire graph of the function is shown.For each

Masja [62]

Summary of even and odd functions

A function f is even if the graph of f is symmetric with respect to the y-axis. Algebraically, f is even if and only if f(-x) = f(x) for all x in the domain of f.

A function f is odd if the graph of f is symmetric with respect to the origin. Algebraically, f is odd if and only if f(-x) = -f(x) for all x in the domain of f.

From the definition itself, we see how can we test if the functions are even or odd.

- First graph (to the left)

From the graph, we see that the function is symmetric with respect to the y-axis because the left side (x<0) is a reflection (along the y-axis) of the right side (x>0), so it is an even function.

- Second graph (to the right)

From the graph, we see that the function is symmetric with respect to the origin, the left side (x<0) is a reflection (along with the origin) of the side to the right (x>0), so it is an odd function.

- First function (to the left)

The function:

$g(x)=5x^2$

is an even function because we see that:

$g(-x)=5\cdot(-x)^2=5x^2=g(x)$

- Second function (to the right)

The function:

$h(x)=-2x^5+3x^3$

is an odd function because we see that:

$h(-x)=-2\cdot(-x)^5+3\cdot(-x)^3=-(-2x^5+3x^3)=-h(x)^{}$

Summary

We have the following results:

- First function (to the left): even

- Second graph (to the right): odd

- First function (to the left): even

- Second function (to the right): odd

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1 year ago