MATHEMATICS MIDDLE SCHOOL

Suppose a laboratory has a 38 g sample of polonium-210. The half-life of polonium-210 is about 138 days. How many half-lives of polonium-210 occur in 1104 days? How much polonium is in the sample 1104 days later?9 ; 0.07 g
8 ; 2,2622 g
8 ; 4.75 g
8 ; 0.15 g

Answers

Answer 1
Answer: To find the number of half lives divide the total number of days by the number of days for 1 half live:

1104 / 138 = 8

There are 8 half lives.

To find the total amount left multiply the starting amount by 1/2 to the 8th power:

38 * 0.5^8 = 0.148 = 0.15 grams

The answer is the last one.
Answer 2
Answer:

Answer:

D. 8; 0.15 g

Step-by-step explanation:

We have been given that a a laboratory has a 38 g sample of polonium-210. The half-life of polonium-210 is about 138 days.

To find the half-lives of polonium-210, we will divide 1104 by 138.

\text{Number of half lives}=\frac{\text{Total days}}{\text{Half-life}}

\text{Number of half lives}=(1104)/(138)

\text{Number of half lives}=8

Therefore, there are 8 half-lives will occur in 1104 days.

A=a\cdot ((1)/(2))^{(t)/(h)}

A=38\text{ g}\cdot (0.5)^{(1104)/(138)}

A=38\text{ g}\cdot (0.5)^(8)

A=38\text{ g}\cdot 0.00390625

A=0.1484375\text{ g}

A\approx 0.15\text{ g}

Therefore, 0.15 gm of the polonium will be left after 1104 days.

Related Questions

sandy has $200 in her bank account. if she writes 6 checks for exactly $19.98, what expression describes the change in her bank account
In the soccer games so far this season, Letty has had 15 goals in 20 attempts at a goal. What is the probability, expressed as a percent, that she will get a goal the next time she tries for one?A) 15% B) 20% C) 60% D) 75%
bag of potatoes weighs 5 pounds the bag is placed on a scale the unit on the scale is ounces what weight does the scale show
How do you estimate 12.062g to the nearest tens of a gram
What is the answer to 1. please explain!

sarah uses a recipe to make 2 gallons of her favorite mixed-berry juice. the containers she plans to use to store the juice have a capacity of 1 pint. how many containers will sarah need ?

Answers

1 gallon = 8 pints, so  2 gallons = 16 pints.
If each container can hold one pint, then she will need 16 containers.
so
1 gallon = 4 quarts
1 quart = 2 pints

g = 4q = q +  q +  q +  q
g   =   2p^+2p^+2p^+2p^ 
 1 gallon equals 8 pints
2 gallons equal 16 pints
 
 
 THe answer is 16 pints         

My number has 2 hundreds and 1 thousand. It has 4 ones and 1 more ten block's than ones blocks

Answers

1254 i believe because 1000 is 1 thousand, 2 hundreds, 1 more tens block than ones block is 5 because there are 4 ones blocks

Final answer:

The question involves identifying a number based on given information about its digits and blocks. To solve this problem, we use place value to determine the number.

Explanation:

The subject of this question is Mathematics. The question involves identifying a number based on given information about its digits and blocks. To solve this problem, we can break down the information and use place value to determine the number.

The number has 2 hundreds, which means it has a value of 200. It also has 1 thousand, which is equal to 1000. Adding those two values, we get 200 + 1000 = 1200.

Next, the number has 4 ones and 1 more ten block than ones blocks. Since there are 4 ones, this value is simply 4. For the ten blocks, we add 1 to 4 to get 5.

Combining the values, we can write the number as 1200 + 50 = 1250.

So, the number described in this question is 1250.

Learn more about Place Value here:

brainly.com/question/35447631

#SPJ2

PLEASE HELP ME!!!!A box of National brand cornflakes is $2.09 for 12 ounces. A box of store label cornflakes is $3.09 for 20 ounces. Find the unit price for each. Assuming both brands taste equally good, which is the better buy, and why? ___________ is the better buy.

Answers

I don't have the answer but all you need to do is divide $3.09 by 20 and $2.09 by 12 and see which is less

Sequence. 4, 13, 28, 49, ?

Answers

Sequence: 4, 13, 28, 49
Now, differences between numbers = 13-4, 28-13, 49-18
= 9, 15, 21
We can see, difference is increasing by 6 at each step, so it would be 27 for next.

Next number = 49 + 27 = 76

In short, Your Answer would be 76

Hope this helps!
you have to list the differnences, then the 2nd differences

4, 13, 28, 49, ?
  9   15  21
      6   6    6
answer: 76

Rewrite the expression as a complex number in standard form a+bi

Answers

Answer:

\textbf{$a + bi = 2 + i$}\n

Step-by-step explanation:

\textup{Given:}\n$$(4 + √(16 - (4)(5)))/(2)$$\n\textup{This can simplified as:}\n\vspace{6mm}\n

$ (4 + \sqrt(-4))/(2)$\vspace{6mm}\n$\implies (4 + 2i)/(2)$\vspace{5mm}\n$\implies 2 \left(  (2 + i)/(2) \right)$\vspace{5mm}\n$$\therefore a + bi = 2 + i$$

The expression

4 + (√(16 - (4)(5)))/(2)

can be rewritten as a complex number in standard form as 4 + i.

How did we get the value?

To rewrite the expression

4 + (√(16 - (4)(5)))/(2)

as a complex number in standard form a + bi, we need to simplify the expression inside the square root and then perform the necessary calculations.

The expression inside the square root is 16 - (4)(5) = 16 - 20 = -4. Since we have a negative value inside the square root, we can rewrite it as 2i√{1} to simplify it.

Now, let's rewrite the expression:

\[4 + (√(16 - (4)(5)))/(2) = 4 + (√(-4))/(2) = 4 + (2i√(1))/(2) = 4 + i√(1)\]

Since √{1} = 1, the expression becomes:

4 + i√{1} = 4 + i

Therefore, the expression

4 + (√(16 - (4)(5)))/(2)

can be rewritten as a complex number in standard form as 4 + i.

learn more about complex number in standardform: brainly.com/question/12241782

#SPJ6

Name an event that would be measure in days

Answers

Hannika, the jewish holiday in december
An event that would be measured in days could be the lifespan of a housefly, or the moon's orbit, or a long festival.
Hope that helped! =)
Other Questions
The price of oil recently went from $9.20 to $11.50 per case of 12 quarts. Find the ratio of the increase in price to the original price.The ratio is(Type a simplified fraction)
(10m2+6mx−11x2)+(−2m2+4mx+4x2)
Justin has three goldfish and one turtle. Write a fraction to represent the part of his pets that are goldfish.
Students and faculty raised $6042 for band uniforms. The faculty raised $1780. Write an equation you can use to find the amount a raised by the students