1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Charra [1.4K]
2 years ago
5

What is the half-life of 20 g of a radioactive sample if 5 g remain after 8 minutes?

Chemistry
1 answer:
Anni [7]2 years ago
5 0

Hello!

The half-life is the time of half-disintegration, it is the time in which half of the atoms of an isotope disintegrate.

We have the following data:

mo (initial mass) = 20 g

m (final mass after time T) = 5 g

x (number of periods elapsed) = ?

P (Half-life) = ? (in minutes)

T (Elapsed time for sample reduction) = 8 minutes

Let's find the number of periods elapsed (x), let us see:

m =  \dfrac{m_o}{2^x}

5 =  \dfrac{20}{2^x}

2^x = \dfrac{20}{5}

2^x = 4

2^x = 2^2

\boxed{x = 2}


Now, let's find the half-life (P) of the radioactive sample, let's see:

T = x*P

8 = 2*P

2\:P = 8

P = \dfrac{8}{2}

\boxed{\boxed{P = 4\:minutes}}\Longleftarrow(Half-Life)\end{array}}\qquad\checkmark

I Hope this helps, greetings ... DexteR! =)

You might be interested in
Which statement is correct about the rate of a chemical reaction? (5 points)
Elza [17]

Answer:

they don't depend on the temperature

6 0
3 years ago
A light twig is barely floating on the surface of water. What will most likely happen to the twig if a drop of dishwashing deter
ankoles [38]
It will sink below the surface. Since dish soap is a surfactant, it will alter the water's surface tension. Lowering the surface tension, the water will no longer be able to support the mass of the twig.
7 0
3 years ago
A sample of 0.200 moles of nitrogen occupies 0.400 L. Under the same conditions, what number of moles occupies 1.200 L
IRISSAK [1]

The number of mole of nitrogen that occupies 1.2 L under the same condition is 0.6 mole

<h3>Data obtained from the question </h3>
  • Initial mole (n₁) = 0.2 mole
  • Initial volume (V₁) = 0.4 L
  • Final volume (V₂) = 1.2 L
  • Final mole (n₂) =?

<h3>How to determine the final mole </h3>

The final mole can be obtained by using the ideal gas equation as illustrated below:

PV = nRT

Divide both side n

PV / n = RT

Divide both side by P

V / n = RT / P

RT / P = constant

V / n = constant

Thus,

V₁ / n₁ = V₂ / n₂

0.4 / 0.2 = 1.2 / n₂

2 = 1.2 / n₂

Cross multiply

2 × n₂ = 1.2

Divide both side by 2

n₂ = 1.2 / 2

n₂ = 0.6 mole

Learn more about ideal gas equation:

brainly.com/question/4147359

#SPJ1

7 0
2 years ago
In a chemical change molecules DO NOT create or break chemical bonds to form a new substance you might be able to observe a chem
vesna_86 [32]

Answer:

false

Explanation:

3 0
3 years ago
Why do crocodiles walk so gayly?
JulsSmile [24]

Answer:

who knows why they could be or  not or maybe they girl crocs and just got there nails done

4 0
3 years ago
Other questions:
  • Bohr looked to improve upon Rutherford’s model of the atom because Bohr thought that Rutherford’s model:
    13·1 answer
  • Suppose you needed to measure exactly 15.0 mL of water for an
    14·2 answers
  • When two hydrogen atoms bond with one oxygen atom to form water what happens to the electrons?
    7·1 answer
  • Convert 22 ml in to liters
    6·1 answer
  • PLEASE ANSWER
    9·1 answer
  • What are the purposes of a chemical equation? Check all that apply.
    13·2 answers
  • A student has a mass of 90 kg what would his weight be on mars if the acceleration due to gravity is 3.7 ?
    8·1 answer
  • What would happen if a person was not able to control his or her internal temperature? the person would start shivering
    13·2 answers
  • . Which of the following do low pressures not produce?
    13·1 answer
  • What mass of ch4 is consumed when 587. 9 kj of energy is evolved from the combustion of a mixture of ch4(g) and o2(g)? show the
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!