Niobium-91 has a half-life of 680 years. After 2,040 years, how much niobium-91 will remain from a 300. 0-g sample? 3 g 18. 75 g 37. 5 g 100. 0 g.

Answers

Answer 1

Answer:

Amount of Niobium-91 initially

= 300/91 =3.2967mol

2040 years = 3 ×680 = 3 half-lives

therefore, amount left = 0.4121mol

mass of Niobium-91 remaining = 0.4121 ×91 =37.5g

Please give brainliest


Related Questions

If i have 10 dogs and 5 of them went away the mother dog had 10 more than she had before then 3 of them went away and she will get 5 more than she had before. How many dogs does she have ?

Answers

Answer:

This problem is asking the question below:

What is 10-5+10-3+5

10-5=5

5+10=15

15-3=12

12+5=17

So, the mother dog had a total of 17 pups

Step-by-step explanation:

Hope this helps! :)
Have a blessed day! :)

PLEASE MARK ME AS BRAINLIEST I REALLY WANT TO LEVEL UP

A recycling bin is shaped like a trapezoid. The bottom 2 angles are 108 degrees. The top left angle is 72 degrees. The front view of a recycle bin is shaped like a trapezoid. What is the measure of the remaining angle? 72° 144° 198° 252°.

Answers

The measure of the remaining angle is 72 degree, the correct option is A.

What is the trapezoid?

A trapezoid, also known as a trapezium, is a flat closed shape having 4 straight sides, with one pair of parallel sides.

Given

A recycling bin is shaped like a trapezoid.

The bottom 2 angles are 108 degrees.

The top left angle is 72 degrees.

The front view of a recycle bin is shaped like a trapezoid is given by;

[tex]\rm \angle 1+ \rm \angle 2+ \rm \angle 3+ \rm \angle4= 360\\\\108+108+72\rm +\angle 4=360\\\\\rm 288+\angle 4 = 360 \\\\\rm \angle 4=360-288\\\\\rm \angle 4=72[/tex]

Hence, the measure of the remaining angle is 72 degree.

To know more about trapezoid click the link given below.

https://brainly.com/question/3319408

Answer: A) 72

Step-by-step explanation: I got it right

Larry started out the week in a new job. He was paid $10 to attend job orientation.
After that he made $6.25 per hour for each hour he worked. Write the equation in
slope-intercept form that represents the equation.

Answers

Answer:

y=6.25x+10

Step-by-step explanation:

6.25 is the rate of change so it is the slope.  10 is what you start with so it is the y- intercept

Tina got $500 for their 20th birthday and invested it in an account earning 1.5% interest compounded annually. Write and solve an exponential equation to determine how long it will take Tina's investment to grow to $800

Answers

a year and 3 months for there investment to grow

3 times x plus 4 is greater than or equal to 4 times the sum of x and 1. (Hint: 4 times the sum means you should write a distributive property problem)

Answers

Given:

3 times x plus 4 is greater than or equal to 4 times the sum of x and 1.

To find:

The inequality for the given statement and solution of the inequality.

Solution:

4 times the sum means a distributive property problem.

Now,

3 times x : 3x

3 times x plus 4 : 3x+4

Greater than or equal to : ≥

4 times the sum of x and 1 : 4(x+1)

So, the inequality is

[tex]3x+4\geq 4(x+1)[/tex]

Using distributive property, we get

[tex]3x+4\geq 4x+4[/tex]

Isolate variable terms.

[tex]4-4\geq 4x+3x[/tex]

[tex]0\geq x[/tex]

It can be written as

[tex]x\leq 0[/tex]

Therefore, the required inequality is [tex]3x+4\geq 4(x+1)[/tex] and the solution is [tex]x\leq 0[/tex].

Select two ratios that are equivalent to 2:9, colon, 9. Choose 2 answers:

Answers

Answer:

4:18 and 6:27

Step-by-step explanation:

Answer:

the correct answer is option b and c

What are 2 numbers that add to 40 and subtract to 10

Answers

Answer:

25 and 15

Step-by-step explanation:

let the 2 numbers be x and y , x > y , then

x + y = 40 → (1)

x - y = 10 → (2)

add the 2 equations term by term to eliminate y

2x + 0 = 50

2x = 50 ( divide both sides by 2 )

x = 25

substitute x = 25 into (1)

25 + y = 40 ( subtract 25 from both sides )

y = 15

the 2 numbers are 25 and 15

which is larger -17/24 or -11/12




Answers

Answer: -11/12
Explanation: -11/12 is larger

Answer:

-17/24

Step-by-step explanation:

Because they are negative numbers, the smaller fraction (when disregarding the negative sign) is always a larger number. -11/12 could be changed to -22/24, and therefore since it is a larger number when disregarding the negative (22/24), it is a smaller number altogether.

-17/24 > -22/24

Simplify each expression.
8(x-4)
-(x-3)
4(x + 3y + 1)
Helppppppp

Answers

1) 8x-32
2) -x+3
3) 4x+12y+4
(i think this a correct..it’s been a while)

Answer:

8(x-4)

8x-32

-(x-3)

-x+3

4(X+3y+1)

4x+12y+4

Step-by-step explanation:

I am not to sure about the 2nd one tho

A tennis ball is dropped from a height of 12 meters. Each time the ball bounces back to 80% of the height from which it fell. Draw a graph to represent the height of the ball after each bounce.

Please help me

Answers

12meters to
80% doesnt its 92 meters%

Samantha withdrew $160 from her bank account.if the balance of the account is now 379.52 what was her balance before the withdraw

Answers

Answer:

It was $539.52

Step-by-step explanation:

Answer:

$539.52

Step-by-step explanation:

Please answer correctly !!!!!!!!!!!!!! Will mark brainliest !!!!!!!!!!!!!!!!!!

Answers

Answer:

bc=12x

ab=17

ac=141

Step-by-step explanation:

bc-12x
an-17
ac-141

In a bird sanctuary, 30% of the birds are
hummingbirds. If there are about 350 birds in
the sanctuary at any given time, how many are hummingbirds?

Answers

Answer:  105 of them are hummingbirds.

Step-by-step explanation:

I there are a total of 350  birds then 30% o 350 will give the number o hummingbirds.

350 of 30%

350 * 0.3 = 105

What is the scale factor from ABC to XYZ?

Answers

6

scale factor:

new image ÷ original image

Here:

24 ÷ 4  = 618 ÷ 3 = 630 ÷ 5 = 6

Answer: A: 6

Step-by-step explanation:

Point (2, 4) is reflected across the x-axis. What are
the coordinates of its image?

Answers

Answer:

The coordinates of its image are (2, -4)

Step-by-step explanation:

Let us revise the rules of reflection across the axes

If the point (x, y) reflected across the x-axis, then its image is (x, -y), the rule of reflection is rx-axis (x, y) → (x, -y) If the point (x, y) reflected across the y-axis, then its image is (-x, y), the rule of reflection is ry-axis (x, y) → (-x, y)

∵ The point (2, 4) is reflected across the x-axis

→ By using the first rule above rx-axis (x, y) → (x, -y)

∴ Change the sign of its y-coordinate

∴ Its image is (2, -4)

The coordinates of its image are (2, -4)

Is it Zero or undefined?

Answers

Answer:

0

Step-by-step explanation:

When trying to solve this we have only y left over. if we only have the slope for y it is 0. if we only have the slope for x it is undefined.

Pls tell me if it is wrong

If it is I am sorry

Find the slope of JK←→ and LM←→−. Then determine whether the two lines are parallel, perpendicular, or neither.

J(1, 9), K(7, 4), L(8, 13), M(-2, 1)

m(JK) =

m(LM) =

Parallel, Perpendicular, or Neither:

Answers

perpendicular"

Step-by-step explanation:

We need to find slope (m) of both line JK and LM

Slope has formula:

Lets find slope of JK:

Lets find slope of LM:

we know if we multiply two lines' slope and get -1, they are perpendicular. Let's check:

Hence, they are perpendicular

At the beginning of the year, John had $40 in savings and saved an additional $13 each week thereafter. Isaac started the year with $80 and saved $9 every week. Let 'J' represent the amount of money John has saved tt weeks after the beginning of the year and let 'I' represent the amount of money Isaac has saved tt weeks after the beginning of the year. Write an equation for each situation, in terms of t, and determine the number of weeks after the beginning of the year until John and Isaac have the same amount of money saved.

Answers

Answer:

10 weeks

Step-by-step explanation:

Let’s replace ‘t’ with numbers going up starting from 0 on both sides of the equation. Repeat until you get to 10 and you see that both are equal at $170 has been saved after 10 weeks.


John’s equation: 40 (y intercept) + 13t (saved per week)

Issac’s: 80 (y intercept) + 9t (amount saved per week)


The y-intercept represents the amount of money already saved up.

729,646 __ 729,054
LESS OR GREATER OR EQUAL.

Answers

Answer:

729,646 > 729,054

Ava bought a rectangular rug for her hallway. The rug is 23 yards wide and 234 yards long. What is the area of the rug?.

Answers

Answer:

5,382 yards

Step-by-step explanation:

To find the area, just multiply the width and length together. Don't forget the unit!!

A graph of a quadratic function is shown on the grid.



Which coordinates best represent the vertex of the graph?
A. (2, -1)
B. (1, 0)
C.(3, 0)
D.(0, 3)

Answers

The coordinate, (2, -1) best represents the vertex.

According to the graph the vertex is the lowest point, the minimum.

Maya runs 7 miles in 50 minutes. At the same rate, how many miles would she run in 75 minutes

Answers

Answer:

10.5 miles

Step-by-step explanation:

Solve for x.
|x =
x = 8
If there is more than one solution, separate them with commas.
If there is no solution, click on "No solution".
X =
No
solution
X Х
?

Answers

9514 1404 393

Answer:

  x = -8, 8

Step-by-step explanation:

The argument of the absolute value function can be positive or negative to give the same result.

  |-8| = 8   ⇒   x = -8

  |8| = 8   ⇒   x = 8

The possible solutions are x = -8, 8.

Which property is x/5=3 pls helppp

Answers

Answer:

It means that the value of X is 15

X/5=3/1

or,X=3×5

or,X=15

Answer:

value of X is 5 ani if there was y then it would be vaule of y

Lance has 3 time as many pencils as Nick, and they have 84 pencils together. How many pencils does each of them have?

Answers

Answer:

21 pencils for Nick and 63 pencils for Lance

Step-by-step explanation:

Lance is said to have 3 times the pencils Nick has.Let's keep the number of pencils Nick has as x.If Nick has x pencils that means Lance has 3x pencils. The total number of pencils present is 84.

Now let's make an equation out of the information above:

3x + x = 84

Now solve for x.

3x + x = 84

4x = 84

x = 84/4

x = 21

So Nick has 21 pencils

Now for Lance:

3x

3 * (21) = 63

So Lance has 63 pencils

63 + 21 = 84 pencils

please HELP ME!!!!! asap

Answers

Answer:

She should ski on Slope B because it is steeper

Step-by-step explanation:

Slope B is steeper than Slope A, so she should ski on Slope B.

First, you must find common multiples for the denominator.

[tex]\frac{15}{24}=\frac{30}{48}[/tex]     slope A

[tex]\frac{12}{16}=\frac{36}{48}[/tex]     slope B

Slope B has a higher vertical feet per 48 horizontal feet, so slope B is steeper.

grete waitz won the new york marathon nine times. The rate at which she ran during her last victory in 1988 was 26 miles in 148 minutes. to the nearest hundredth, what was the unit rate for her last race.

Answers

Answer

148/26 = 5.69  min/mile

Step-by-step explanation:

Unit rate    miles per minute  =    26/148 = 0.175= 0.176 miles per minute (rounded)

If you want minutes per mile  148/26 = 5.69  min/mile      

Please help I think I have an idea as to what it is but I think somethings off with what I got (Due in 8 minutes!! have a blessed day/night)

Answers

Answer:

i think its 13 im not too sure. Im not that good at math

Step-by-step explanation:

yall i need help its de in 30mins!!​

Answers

Answer:

I can solve partial

Step-by-step explanation:

Given that,

Diameter of semicircle= 5m

Radius= 2.5m

Now,

Perimeter= πr

=3.14×2.5

= 7.85

Does the graph represent y as a function of x?

Answers

Answer:

No this is not a function

Step-by-step explanation:

If you use the vertical line test which is just a line used across the graph. If we can draw any vertical line that intersects a graph more than once then it is not a function.

Other Questions
Two parallel plates having charges of equal magnitude but opposite sign are separated by 29.0 cm. Each plate has a surface charge density of 32.0 nC/m2. A proton is released from rest at the positive plate. (a) Determine the magnitude of the electric field between the plates from the charge density. kN/C (b) Determine the potential difference between the plates. V (c) Determine the kinetic energy of the proton when it reaches the negative plate. J (d) Determine the speed of the proton just before it strikes the negative plate. km/s (e) Determine the acceleration of the proton. Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. m/s2 towards the negative plate (f) Determine the force on the proton. N towards the negative plate (g) From the force, find the magnitude of the electric field. kN/C (h) How does your value of the electric field compare with that found in part (a) Entrepreneurship helps to create new businesses resulting in new employment and can produce a favorable and positive effect in the economy.True or false Which of the following is an advantage of a low center of gravity?It is easier to stay balancedIt is easier to lift your body upIt is easier to flyIt is easier to jump(I could not find an option for science so I just made the subject math instead but this is sciences) Help me please please please the service to India mail service to the _________ to suffer who controls the congressional election process? Are the given lines parallel? Explain your reasoning.3. y = 2, y = -4 Whats the difference between the speaker of the house and the senate majority leader? 161. Robber baron is a sarcastic term used for a powerful business man in 19th centuryAAmerican Business manB British BusinessmanC French DusinessmanDNone of the Above What are base unit measurements for the metric system?A. feet, gallon and poundB. grams, liters, and meters C. Liters, pints, and milesD. millilites, milligrams and millimeters Research in plant biotechnology has focused primarily on characteristics thatQuestion 10 options:improve resistance to pests, reduce the need for pesticides, and increase survival rates in adverse growing conditions.reduce the need for other genes to be introduced into a plant genome.allow genetically engineered seeds to be prepared within two months.allow genetically engineered seeds to double in size within one year. A rectangular park is w feet wide. Its length is 25 feet larger than its width. Record using algebra:What is the length of the park? 5(x2)3(2x) pls answer pls i need help How does a website address help you evaluate the reliability of a website? (5 points)Group of answer choicesCertain website addresses guarantee that the information is reliable.The website address provides clues about the expertise of authors.When a website is published by a university, the information is always reliable.Some website addresses are considered more reliable than others. Which explicit detail best supports the inference that Karen missed her bus toschool?Karen was running. Her legs were tired, and she was panting. Suddenly,she stopped and looked upset. The school bus zoomed past her."Stop!" she yelled at the bus. "Wait for me!"A. The school bus drives past her.B. She is running because she is late,C. She is out of shape.D. She yells at the bus to wait for her, Please help ASAPI need help Maps that focus on ideas are known as what?A. politicalB. physicalC. humanD. special purpose i need asap i will mark brainliest What do meteorologists do?A. create special purpose maps and globesB. predict weather patternsC. analyze population patternsD. keep count of populations in specific areas Chad and his two friends are picking blueberries at a local farm. Chad picked 2 pounds of blueberries, and one of his friends picked 1 pounds. If they ended up with a total of 5 pounds, how many pounds did Chad's other friend pick? Express your answer as a mixed number.