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2 years ago

Please help guys!!! Points + Brainliest

Mathematics

2 answers:

Bas_tet [7]2 years ago

8 0

Protons and electrons are 12. For neutrons, there are 12 of them.
Magnesium has an atomic number of 12, which means there are 12 protons.
You subtract the atomic number from the mass number in order to find neutrons.
Atomic mass is 24. 24-12=12
Electrons always match the number of protons.

Ipatiy [6.2K]2 years ago

5 0

Answer:

Part 2:

There are 19 protons in the element K, you can tell because of the number 19 above the elements abbreviation. There are also 19 electrons in this element, you can tell because the number of protons is the same number of electrons. Last, to find the number of neutrons an atom possesses, you have to round the atomic mass ( 39.089 to 39 ). Then you take your Mass number ( 39 ) and subtract it from your number of protons (19). 39 - 19 = 29, there are 29 neutrons in the element K.

Hope that this helps! :)

Also if you need part 1 :)

Part 1:

The two-element that has the same properties as Magnesium are Calcium (Ca) and Strontium (Sr). These three elements are all Alkaline earth metals, they are not as reactive as Alkali metals but they are too reactive to be found in nature.

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BRUH WHY DO YOU GUYS NOT ANSWER MY QUESTIONS DO YOU NOT KNOW HOW IMPORTANT THIS IS?!

iren2701 [21]

Answer:

the two graph depicting proportional relationships are the top right and bottom left graphs

hope this helps and btw maybe make ur questions worth more points and dont make titles like this one lol also if its worth like 15 or more points put "__ POINTS"

have a great day!

8 0

3 years ago

The length of a rectangle is twice its width. Find its area, if its perimeter is 7 and 1/3 cm.

laila [671]

Answer:

2.99 cm²

Step-by-step explanation:

(The "..." at the end of the decimal means that number is repeating)

The perimeter of a rectangle is the length around the shape. The equation for a rectangle's perimeter is L + W × 2, with L and W representing length and width, respectively (You multiply the length and width by two because the shape is four-sided, so it has two length sides and two width sides). To find the area of the rectangle, you need to know the individual length and width, so you'll solve for that first.

Since you're only given the perimeter and you know the length is double the width, you'll need to work backwards with this equation. To do this, first divide the perimeter (7 $\frac{1}{3}$ , also written as 7.33...) by 2; this equals 3 $\frac{2}{3\\}$ , also written as 3.66...

Next, you can find the length and width by determining what two numbers multiply to equal 3.66..., with one number being two times larger than the other number. The way I tend to think of this is that if one number is double the other, then the smaller number is one third of the sum of the two numbers (since the smaller number represents one part of the sum, and the other represents two parts of the sum, which is double the smaller number).

Since the length and width combine to be the divided perimeter, 3.66..., that means two thirds of 3.66... is the longer side (the length), and then the one third of 3.66... is the shorter side (the width). This means the length is 2.44... and the width is 1.22...

Finally, you can solve for the perimeter by dividing the perimeter by two and then subtracting the length squared. The written equation looks like this:

A = P $\frac{1}{2}$ - L²

(A = area, P = perimeter, L = lenth)

Now just insert the numbers into the equation and solve!

The area of the rectangle is 2.99cm²

7 0

2 years ago

Give the degree of the polynomial

OLEGan [10]

Answer

it is the highest power combined that one expression has, in this case its 5u^8, thus the degree is 8

3 0

2 years ago

Read 2 more answers

A pencil at a stationery store costs $1, and a pen costs $1.50. Stefan spent $7 at the store. He bought a total of 6 items. Whic

LekaFEV [45]

Well, the first one, I have never worked with before so I'm sry but I can't help you with that one. 3y + x = 4 (x=1) 2y - x = 6 (x=8)

4 0

2 years ago

Identify the type of conic section that has the equation 9x2+ 16y2 = 144 and identify its domain and range.

Kobotan [32]

9 x² + 16 y² = 144 /:144
$\frac{ x^{2} }{16} + \frac{ y^{2} }{9} =1$
General formula of ellipse ( the center is at the origin ): $\frac{ x^{2} }{ a^{2} }+ \frac{ y^{2} }{ b^{2} } =1$
a² = 16, b² = 9
Domain: [-a, a ] = [-4, 4]
Range:[-b, b ]
Answer: B ) ellipse.
Domain: { -4 ≤ x ≤ 4 }
Range: { -3 ≤ y ≤ 3 }

8 0

2 years ago