I missed a whole lesson plz explain

The radioactive isotopes of an element are known as radioisotopes.  The radioisotope sample that is given is Barium-139.

The radioactive isotopes of an element are known as radioisotopes. Atoms with an unstable mix of neutrons and protons, or excess energy in their nucleus, are also known as neutron-proton atoms.

As it is given that the initial mass of the sample at 12:02:00 PM is,

[tex]m_1=104.8\ kg[/tex]

The Mass of the sample at 4:11:00 PM is given as

[tex]m_2 = 13.1 kg[/tex]

So here since it is a sample of radioactive isotope so here we will say

[tex]m_2=m_1e^{-\lambda t}[/tex]

Now from the above data, we know that the time taken to reduce the mass is

[tex]\rm t = 4\ hours\ 9\ minutes = 4.15\ hours[/tex]

Further, from the above equation, we will have

[tex]13.1 =104.8 e^{-\lambda(4.15)}\\\\\lambda(4.15)=2.08\\\\\lambda = 0.50/ hour[/tex]

So here half-life is given as

[tex]\rm T_{\frac12}=\dfrac{ln2}{\lambda}\\\\ T_{\frac12} = 1.4\ hours[/tex]

Thus, here this isotope must be the one that will have a half-life of 1.4 hours

Therefore, it is nearly Barium-139.

Hence, the radioisotope sample that is given is Barium-139.

Learn more about Radioisotope:

https://brainly.com/question/49002

Answer:

A

Step-by-step explanation:

Addition Property of Equality

If two expressions are equal to each other, and you add the same value to both sides of the equation, the equation will remain equal.

Hope this helps! Please let me know if you need more help or think my answer is incorrect. Brainliest would be MUCH appreciated. Have a wonderful day!

Answer:

The answer is 13

Step-by-step explanation:

ABC is equal to GHI, so AB = GH which is 13

Answer:

80 / C

Step-by-step explanation:

Easy peasy 161 divided by 2 is 80.5, but you can't buy half of a sign. Round downwards.

Answer:

C

Step-by-step explanation:

Answer:  n ≤ 52

Step-by-step explanation:

less than or equal to is usually write as ≤.

n - 15 ≤ 37

  +15    +15 [Add 15 to the both sides]      

     n ≤ 52

Answer:

1 quart = 32 ounces

so we have 64 ounces

8.32 ÷ 64 ounces = $0.13 per ounce

Answer:

The actual length of the room is 40 feet

Step-by-step explanation:

Given

[tex]Scale = \frac{1}{2}\ inch : 12\ feet[/tex]

Required

Determine the actual measurement of [tex]3\frac{1}{3}\ inches[/tex]

Represent the required actual measurement with x

i.e.

[tex]3\frac{1}{3}\ inches : x[/tex]

And we have:

[tex]\frac{1}{2}\ inch : 12\ feet[/tex]

[tex]3\frac{1}{3}\ inches : x[/tex]

Cross Multiply

[tex]x * \frac{1}{2} = 12 * 3\frac{1}{3}[/tex]

Convert fraction to improper fraction

[tex]x * \frac{1}{2} = 12 *\frac{10}{3}[/tex]

[tex]\frac{x}{2} = \frac{120}{3}[/tex]

[tex]\frac{x}{2} = 40[/tex]

Multiply both sides by 2

[tex]x = 40 * 2[/tex]

[tex]x = 80\ feet[/tex]

The actual length of the room is 40 feet

Answer:

it is 7/34

Step-by-step explanation:

The Median is 1 squared

Answer:

.8888888889

Step-by-step explanation:

caculator

Step-by-step explanation:

First we solve it.

I'll use substitution.

In the first equation y equals -2x+2 so we can apply that to the second equation

2y + 4x = 4

2(-2x+2) + 4x = 4

distribute

-4x+4+4x=4

simplify

4=4

To figure out how many solutions it has:

•If both side of the equal sign are exactly the same: Infinitely many

ex: 6x=6x

•If both sides of the equal sign do not match when completely simplified: No solutions

ex: 3x=-5x

•If it creates an equation: 1 solution

ex: x=3+2y

Since both sides of the equal sign are 4, we have infinitely many solutions.

Hope this helps! If you have any questions on how I got my answer feel free to ask. Stay safe!

Still stuck? Get 1-on-1 help from an expert tutor now.

Step-by-step explanation:

Train 1 speed be 'u'

Train 2 speed be 'v'

And v=2u

Speed=distance/time

Trains going in opposite directions

Relative speed= v-u (as train 1 I slower than train 2)

v-u=600/4

2u-u=150

u=150miles/hour

v=300miles/hour

x = 25

Hi there !

4x - 25 = 25 + 2x

4x - 2x = 25 + 25

2x = 50

x  = 50 : 2

x = 25

Good luck !

Answer:

85

Step-by-step explanation:

We will use the formula

xbar = \sum Xi/N

xbar is the average

N is the number of rounds

\sum Xi is sum of rounds

From the formula:

\sumXi = xbar × N.

If Gabby has entered a cooking contest with 6 rounds and in order to earn a medal, she needs a final average score higher than 75, this means that;

N = 6

xbar = 75+x (since her average needs to be more than 75)

Substitute in the formula

\sumXi = 6(75+x) ....... 1

If after the first five rounds, her average score is 78, then:

At N = 5, xbar = 78

Substitute into the formula

\sumXi = 5(78)

\sumXi = 390..... 2

First we need to get x by equating equation 1 and 2:

6(75+x) = 390

450 + 6x = 390

6x = 390-450

6x = -60

x = -10

Taking x as 10

Since she needs 75+x to earn the medal, substitute x = 10 into the expression:

This means that she will need average score of 75+10 i.e 85 to win the medal

Answer:

b

Step-by-step explanation:

you aint got enough information

Answer:

C

Step-by-step explanation:

10*.9=9

12+z=56

z=56-12

z=44

26-x=17

-x=17-26

-x=-9

x=9

8+5z=43

5z=43-8

5z=35

z=35/5

z=7

Answer:

12

Step-by-step explanation:

Solution:

We know that:

Substituting the height and the area of the pane in the formula

Simplifying the LHS:

Dividing 24 both sides

Thus, the measure of the base is 24 inches.

Answer:

10

Step-by-step explanation:

Answer:

the correct answer for the rectangular prisim is 32

The surface are of the rectangular cuboid is 32.

1. Label the length (l), width (w), and height (h) of the prism

2. Use the formula, SA=2lw+2lh+2hw, to find the surface area.

Another option:

- Add the areas of all 6 faces

Answer:

3m+4n

Step-by-step explanation:

5m-2m=3m 3n+n=4n so 3m+4n

The histogram showing the number of events with the events cost is

misleading because;

Please find attached a possible diagram of the histogram in the question

created with MS Excel;

The data in the histogram is presented as follows;

[tex]\begin{array}{|c|c|c}Event \ Cost&Number \ of \ Events\\1000- 1499&2\\1500-1999&4\\2000-2499&3\\3000-3499&1\end{array}\right][/tex]

From the above table, we have that the class with event cost of 2000 to

2499 is left out, therefore, the data is more clustered.

The correct option is therefore;

The x-axis scale shows the data is more clustered than it actually is

Learn more about histograms here:

https://brainly.com/question/1413492

Answer:

its a

Step-by-step explanation:

got it right on edge

Answer:

x² + 8x + 16

Step-by-step explanation:

(x + 4)²

= (x + 4)(x + 4)

Each term in the second factor is multiplied by each term in the first factor, that is

x(x + 4) + 4(x + 4) ← distribute parenthesis

= x² + 4x + 4x + 16 ← collect like terms

= x² + 8x + 16

Step-by-step explanation:

1.

x=5

y=4

2.x=4.2

y=19.8

3. x=16

y=70.4

4. a=28

b=25/7

5.a=20

b=18

6. a=51

b=75

7. x=30

y=21

8.a=27

b=6

hope it helps:)

ignore that fig '-'

Answer:k

Step-by-step explanation:

Answer:

count 1035 28 times i guess.

Step-by-step explanation:

Answer:

Euler, Descartes, Gauss, Archimedes, Hypatia

Step-by-step explanation:

I just used a logic puzzle format thing so its rly hard to explain in words but I hope this helped and if you have any specific questions you can comment and ask! Also welcome to brainly if youre new (your question has the first question banner on it ) and also if you think my answer deserves brainliest i would really appreciate it! It would also be amazing if ppl would rate this answer so future users know if it's right!

Answer:

19

Step-by-step explanation:

Answer: 26 degrees

Step-by-step explanation:

Answer:

x=9/6

Step-by-step explanation:

[tex] \frac{20}{16 } = \frac{12}{x} [/tex]

12×16=192

192÷20=9.6

Answer:

A and C

Step-by-step explanation:

m =  1 - (-1) / 3-2 = 2/1 = 2

m = -3 - (-1) / 1 - 2 = -2/-1 = 2

An equation is formed when two equal expressions are equated together with the help of an equal sign '='. The value of y in the equation is -1.5.

An equation is formed when two equal expressions are equated together with the help of an equal sign '='.

The value of y in the equation can be found in the following manner,

[tex]2y=-3\\\\y=\dfrac{-3}{2}\\\\y = -1.5[/tex]

Hence, the value of y in the equation is -1.5.

Learn more about Equation:

https://brainly.com/question/2263981

Answer:

-1

Step-by-step explanation: