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2 years ago

How many protons are in an element with an atomic number of 8 and a mass number of 18?

Mathematics

2 answers:

Orlov [11]2 years ago

8 0

A)8,atomic number also means proton number

aleksandrvk [35]2 years ago

4 0

Since the atomic number is 8 that will be the number of protons given that the element is a neutral element meaning that the number of protons and electrons are the same. Therefore the answer is 8

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Find the inverse of the function f(x) = (x - 4) 2 - 5 if x ≥ 4.

Serggg [28]

Same here, we do a quick switcharoo on the variables first,

$\bf \stackrel{f(x)}{y}=(x-4)^2-5\qquad inverse\implies \boxed{x}=\left( \boxed{y}-4 \right)^2-5
\\\\\\
x+5=(y-4)^2\implies \pm\sqrt{x+5}=y-4\implies \pm\sqrt{x+5}+4=y$

6 0

2 years ago

Q5: The probability that event A occurs is 5/7 and the probability that event B occurs is 2/3 . If A and B are independent event

bekas [8.4K]

Answer:

$P(A \cap B)$

And we can use the following formula:

$P(A \cap B)= P(A)* P(B)$

And replacing the info we got:

$P(A \cap B) = \frac{5}{7} \frac{2}{3}= \frac{10}{21}=0.476$

Step-by-step explanation:

We define two events for this case A and B. And we know the probability for each individual event given by the problem:

$p(A) = \frac{5}{7}$

$p(B) = \frac{2}{3}$

And we want to find the probability that A and B both occurs if A and B are independent events, who menas the following conditions:

$P(A|B) = P(A)$

$P(B|A) = P(B)$

And for this special case we want to find this probability:

$P(A \cap B)$

And we can use the following formula:

$P(A \cap B)= P(A)* P(B)$

And replacing the info we got:

$P(A \cap B) = \frac{5}{7} \frac{2}{3}= \frac{10}{21}=0.476$

7 0

2 years ago

The lid for a circular plastic food container has a diameter of 9 cm.

Levart [38]

If the diameter is 9 cm the radius is 4.5 cm (half the diameter). The area of a circle is given by the formula: 4πr^2, where π is the constant ratio of circumference to diameter (3.14159...).

3.14 cm x 4.5 cm = 14.13 cm^2. Remember, the units must be squared to represent area. 14.13 is extended to the nearest hundredth.

5 0

3 years ago

Will give you brainiest

BabaBlast [244]

Answer:

$\boxed{$

Step-by-step explanation:

A) If AB is a diameter, Then ACB is a 90 degrees angle because In a semi-circle (AB is a diameter which divides the circle into 2 equal parts), the angle opposite to the diameter is of 90 degrees.

So, <ACB = 90 degrees

Then <a = 180-90-28

=> <a = 62 degrees

B) The opposite interior angles of a quadrilateral inscribed in a circle add up to 180 degrees.

So,

=> <a + <b = 180

=> <b = 180-62

=> <b = 118 degrees

3 0

2 years ago

What is -5x^2+7x+1 from 8x^2+x-10

Oliga [24]

Answer:

13x^2 - 6x -11

Step-by-step explanation:

8 0

2 years ago