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
gizmo_the_mogwai [7]
3 years ago
12

What is the half life of a radioisotope if you started with 1 gram and 0.250 grams is left over after 6 days?

Chemistry
1 answer:
jolli1 [7]3 years ago
4 0

Answer:

3 DAYS

Explanation:

Half-life is the time required for a quantity of a radioisotope to reduce to half its initial value. It is represented as t1/2

In the question given,

t1/2 = 3 days

Since 1 gram of the radioisotope divides to half and give 0.5 grams = t1/2

Subsequently division yields;

1gram = 0.5 gram in 3 days

0.5 gram = 0.250 grams = 3 days

This is so because after 6 days, 0.250 gram of the radioisotope is remaining.

You might be interested in
After the solution reaches equilibrium, what concentration of Ni2+(aq) remains? The value of Kf for Ni(NH3)62+ is 2.0×108. Expre
Marina CMI [18]

Answer:

\large \boxed{1.77 \times 10^{-5}\text{ mol/L}}

Explanation:

Assume that you have mixed 135 mL of 0.0147 mol·L⁻¹ NiCl₂ with 190 mL of 0.250 mol·L⁻¹ NH₃.

1. Moles of Ni²⁺

n = \text{135 mL} \times \dfrac{\text{0.0147 mmol}}{\text{1 mL}} = \text{1.984 mmol}

2. Moles of NH₃

n = \text{190 mL} \times \dfrac{\text{0.250 mmol}}{\text{1 mL}} = \text{47.50 mmol}

3. Initial concentrations after mixing

(a) Total volume

V = 135 mL + 190 mL = 325 mL

(b) [Ni²⁺]

c = \dfrac{\text{1.984 mmol}}{\text{325 mL}} = 6.106 \times 10^{-3}\text{ mol/L}

(c) [NH₃]

c = \dfrac{\text{47.50 mmol}}{\text{325 mL}} = \text{0.1462 mol/L}

3. Equilibrium concentration of Ni²⁺

The reaction will reach the same equilibrium whether it approaches from the right or left.

Assume the reaction goes to completion.

                        Ni²⁺             +             6NH₃       ⇌       Ni(NH₃)₆²⁺

I/mol·L⁻¹:    6.106×10⁻³                     0.1462                       0

C/mol·L⁻¹:  -6.106×10⁻³         0.1462-6×6.106×10⁻³             0

E/mol·L⁻¹:           0                              0.1095                6.106×10⁻³

Then we approach equilibrium from the right.

                            Ni²⁺   +   6NH₃       ⇌       Ni(NH₃)₆²⁺

I/mol·L⁻¹:              0           0.1095                6.106×10⁻³

C/mol·L⁻¹:            +x            +6x                           -x

E/mol·L⁻¹:             x         0.1095+6x            6.106×10⁻³-x

K_{\text{f}} = \dfrac{\text{[Ni(NH$_{3}$)$_{6}^{2+}$]}}{\text{[Ni$^{2+}$]}\text{[NH$_{3}$]}^{6}} = 2.0 \times 10^{8}

Kf is large, so x ≪ 6.106×10⁻³. Then

K_{\text{f}} = \dfrac{\text{[Ni(NH$_{3}$)$_{6}^{2+}$]}}{\text{[Ni$^{2+}$]}\text{[NH$_{3}$]}^{6}} = 2.0 \times 10^{8}\\\\\dfrac{6.106 \times 10^{-3}}{x\times 0.1095^{6}} = 2.0 \times 10^{8}\\\\6.106 \times 10^{-3} = 2.0 \times 10^{8}\times 0.1095^{6}x= 345.1x\\x= \dfrac{6.106 \times 10^{-3}}{345.1} = 1.77 \times 10^{-5}\\\\\text{The concentration of Ni$^{2+}$ at equilibrium is $\large \boxed{\mathbf{1.77 \times 10^{-5}}\textbf{ mol/L}}$}

 

3 0
3 years ago
What role does the rock play
goldfiish [28.3K]
Rocks are part of our planet. They tell stories like how they were formed and which environment they belong in. And it also tells us things about the past, because rocks came long before humans did.
8 0
3 years ago
Read 2 more answers
1. Identify the type of ecosystem service being provided in each of the following
Wittaler [7]

The ecosystem services provided by the each of the given examples are as follows:

  • A cornfield in Kansas provides provisioning services.
  • Bacteria that decompose waste along the Gulf Coast provides regulating services.
  • Ocean currents that keep Pacific Northwest air cool and moist provides regulating services.
  • Flower garden at a national landmark provides cultural services.
  • Lumber from an oak tree provides provisioning services.
  • Animals that eat seeds and then spread the seeds through their waste regulating services.

<h3>Ecosystem services</h3>

Ecosystem services are defined as the benefits derived by man from the surroundings ecosystems.

<h3>Categories of ecosystem services</h3>

The four categories of ecosystem services are:

  • regulating services,
  • provisioning services,
  • cultural services, and
  • supporting services

A cornfield in Kansas provides provisioning services.

Bacteria that decompose waste along the Gulf Coast provides regulating services.

Ocean currents that keep Pacific Northwest air cool and moist provides regulating services.

Flower garden at a national landmark provides cultural services.

Lumber from an oak tree provides provisioning services.

Animals that eat seeds and then spread the seeds through their waste regulating services.

Learn more about ecosystem services at: brainly.com/question/2191258

7 0
2 years ago
What would happen if the earth magnetic field flips? <br><br> plz help
Mumz [18]

The end of the world as we know it could come in any number of ways, depending on who you ask. Some people believe global cataclysm will occur when Earth's magnetic poles reverse. When north goes south, they say, the continents will lurch in one direction or the other, triggering massive earthquakes, rapid climate change and species extinctions.

 

The most dramatic changes that occur when the poles reverse is a very large decrease of the total field intensity,

Earth's magnetic field takes between 1,000 and 10,000 years to reverse, and in the process, it greatly diminishes before it re-aligns. It's not a sudden flip, but a slow process, during which the field strength becomes weak, very probably the field becomes more complex and might show more than two poles for a while, and then builds up in strength and [aligns] in the opposite direction.

8 0
3 years ago
The moon will always appear over the eastern horizon at the same time each night. true or false
Otrada [13]
False it will be false

7 0
3 years ago
Other questions:
  • What is the main difference between an isotope and an ion?
    13·2 answers
  • BRAINLIESTTT ASAP!! PLEASE HELP ME :)
    14·2 answers
  • Water beads up on waxy surfaces because of a ___________ degree of adhesion with the surface?
    6·2 answers
  • Please help me with question number 7 if you need help read the article on top
    14·1 answer
  • Since density depends on the mass and volume of an object, we need both of these values combined in the correct way to solve for
    15·1 answer
  • 8CO + 17H2 → C8H18 + 8H2O
    9·1 answer
  • If water isn’t a good conductor of electricity why can’t people swim during a thunderstorm?
    14·1 answer
  • What is the best description
    15·2 answers
  • Mole ratio compares the subscripts of two compounds in a balanced reaction.
    10·1 answer
  • Which classes of isomers are easier to separate from each other in the laboratory: enantiomers or diastereomers?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!