PHYSICS MIDDLE SCHOOL

A sample contains 100 g of a radioactive isotope. How much radioactiveisotope will remain in the sample after 2 half-lives? OA. 50 g
OB. 25 g
OC. 75 g
OD. 100 g

Answers

Answer 1
Answer:

Answer:

B. 25 g

Explanation:

Given:

The initial mass of radioactive isotope is, m_0=100\ g

There is exponential decay of the isotope with time.

Half life means the time in which the given mass reduces by half. For every half life, the mass reduces by half of the previous mass.

So, for the first half life, the mass that remains is given as:

m_1=(m_0)/(2)=(100)/(2)=50\ g

Now, for the second half life, the mass 50 g is again reduced to half.

So, the mass that remains after 2 half-lives is given as:

m_2=(m_1)/(2)=(50)/(2)=25\ g

Therefore, the radioactive isotope that will remain in the sample after 2 half-lives is 25 g.
Answer 2
Answer:

Answer:

its 12.5 g for anyone else who had different options

Explanation:

Related Questions

1.    How does the friction affect forwardmotion? Give an example. 2.    Describe two ways to change the frictional force between two solids surfaces. Change the lubrication between the two surfaces Change the normal force between the two surfaces3.    How does air resistance affect the velocity of a falling object? 4.    What two sources of friction do you have to overcome when you are walking? 5.    If you push a chair across the floor at a constant velocity, how does the force of friction compare with the force exert? Explain. 6.    If you push a book against a wall hard enough, it will not slide down even though gravity is pulling it. Use what you know about Newton’s laws of motion to explain why the book doesn’t fall.
People in the United States know that water boils at 212 Degrees Fahrenheit. In Europe, people know that water boils at 100 degrees Celsius. Is the water in the U.S. different than the water in Europe? What explains the two different temperatures
A star has a size of 0.1 solar radius. How many times larger is the sun than this star?
O núcleo de um átomo possui 5 prótons e 6 nêutrons.Determine o número atômico (Z) r o.número de massa (A)
near the earth surface the amount of mass an object has does not affect its acceleration due to gravity

How does the mass of an object affect its acceleration during a freefall?

Answers

There is a big misconception about this but I will try to clear it up:
Think about this, if you drop a feather and a marble from the same beginning point then they will both fall at the same rate. This is because, mass doesn't affect the speed of falling objects, however, if there are other factors involved other than gravity then the answer may vary.

Hope this helped

A small child has a wagon with a mass of 10 kilograms. The child pulls on the wagon with a force of 2 Newtons. What is the acceleration of the wagon? 

Answers

We know that Force (F) is equal to mass (m) times the acceleration (a)
Mathematically,
F=m.a

Here:
m=10 and F=2
by solving for a we get a = 0.2 meters per second squared.
the answer is 0.2 meter per second squared.

A player kicks a ball with a force of 5 N. The ball travels 10 meters. What was thetotal amount of work?
O ou
O su
50 u
o 500
O
1000 J

Answers

The total amount of work done will be "50 J". To understand the calculation, check below.

Work done and Force

According to the question,

Force, F = 5N

Distance, d = 10 m

We know the formula,

→ Work = Force × Distance

or,

→ W = F × d

By substituting the values, we get

       = 5 × 10

       = 50 N/m or,

       = 50 J

Thus the response above is correct.

Find out more information about force here:

brainly.com/question/25239010

Answer:

50N/m or 50J

Explanation:

Work is defined as product of force & distance. Hence per the parameters,

Force = 5N and Distance is 10m

Therefore Work =F x d

Work = 5N x 10m

Work =50N/m or 50J

What process, driven by heat generated from within the Earth's core, occurs in the mantle and is a primary cause of plate tectonics?A.faulting
B.mantle convection
C.subduction
D.trench formation

Answers

Answer:

The correct option is (B)mantle convection

Explanation:

Tectonic plates at the earth's surface move because of the intense heat in the Earth's core. this heat causes molten rock in the mantle layer to move. It moves in a pattern called a convection cell and producing a movement called mantle convection which is the slow creeping motion of Earth's solid silicate.
The answer is B. Mantle convection.

A spoon can sound like bell no this  is not  a riddle  it science prove it

Answers

Metals have a property of being sonorous, that is they make ringing sounds when stuck hard and dpoon and bell both are made of metals.

True or false: distance traveled and displacement can be equal.

Answers

Answer:

true

Explanation:

Answer:

When the object is moving in a straight line distance will be equal to displacement. ... Shortest path = Actual path,because object travelled in a straight line. Displacement and Distance should have same magnitude because the object has not changed its direction.

Explanation:
Other Questions
List the three ways in which water reaches the atmosphere and tell which way accounts for the most of the water in the atmosphere
How do color affect soil
During which season is the sun highest in the sky? A.springB.summerC.fallD.winter(this is science)
There are three different types of electrochemical cells.True or False​