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
7nadin3 [17]
1 year ago
10

lodine-131 is a radioactive isotope with a half-life of 8 days. How many grams of a 50 g sample will be left after 48 days?

Chemistry
1 answer:
RSB [31]1 year ago
4 0

Answer:

0.805 or 0.781 depending on the method used.

Explanation:

<u>Data</u><u> </u><u>provided</u>

half life ie t1/2= 8days.

No= 50g

t=48days

Nt=?

<u>Metho</u><u>d</u><u> </u><u>1</u>

<u>Formul</u><u>a</u><u>:</u><u> </u><u>N</u><u>t=</u><u> </u><u>No</u><u>(</u><u>1</u><u>/</u><u>2</u><u>)</u><u>^</u><u>n</u>

where n= number of half lives.

= t/t1/2 = 48/8

=6.

thus Nt= 50(1/2)^6= 0.781

<u>Metho</u><u>d</u><u> </u><u>2</u>

<u>Formul</u><u>a</u><u>:</u><u> </u><u>Nt</u><u>=</u><u> </u><u>Noe^-</u><u>(</u><u>lambda</u><u>)</u><u>t</u>

where lambda= decay constant

= ln2/ t1/2= ln2/ 8 = 0.086.

thus Nt= 50e^-(0.086×48)= 0.805.

You might be interested in
HCI
Alecsey [184]

Answer:

blood

Explanation:

D

5 0
3 years ago
Read 2 more answers
What are the representative elements usually called
antiseptic1488 [7]

Answer:

There are two sets of groups in the periodic table. The first set are Group A elements and are also known as representative elements. The second set are Group B elements and are also known as transition metals. Representative elements are the most abundant elements on earth.

4 0
3 years ago
Why is desertification a problem?
Gnesinka [82]
Because if all the trees and grasslands are to disappear and turn into deserts then there would be no oxygen for us
6 0
2 years ago
Read 2 more answers
How many joules of heat are absorbed when 1000g of water is heated from 18Celsius to 85celsius?
o-na [289]

Answer + Explanations

Calculate heat absorption using the formula:

Q = mc∆T

Q means the heat absorbed, m is the mass of the substance absorbing heat, c is the specific heat capacity and ∆T is the change in temperature.

The heat absorbed is calculated by using the specific heat of water and the equation ΔH=cp×m×ΔT. 4. Water is vaporized to steam at 100oC. The heat absorbed is calculated by multiplying the moles of water by the molar heat of vaporization.

You can do this easily: just multiply the heat capacity of the substance you're heating by the mass of the substance and the change in temperature to find the heat absorbed.

To calculate the amount of heat released in a chemical reaction, use the equation Q = mc ΔT, where Q is the heat energy transferred (in joules), m is the mass of the liquid being heated (in kilograms), c is the specific heat capacity of the liquid (joule per kilogram degrees Celsius), and ΔT is the change in ...

Q = mc∆T. Q = heat energy (Joules, J) m = mass of a substance (kg) c = specific heat (units J/kg∙K) ∆ is a symbol meaning "the change in"

Precisely, water has to absorb 4,184 Joules of heat (1 calorie) for the temperature of one kilogram of water to increase 1°C. For comparison sake, it only takes 385 Joules of heat to raise 1 kilogram of copper 1°C.

A reaction that absorbs heat is endothermic. Its enthalpy will be positive, and it will cool down its surroundings. This reaction is exothermic (negative enthalpy, release of heat).

Quantitative experiments show that 4.18 Joules of heat energy are required to raise the temperature of 1g of water by 1°C. Thus, a liter (1000g) of water that increased from 24 to 25°C has absorbed 4.18 J/g°C x 1000g x 1°C or 4180 Joules of energy.

6 0
3 years ago
Carbon dioxide is a colorless odorless gas why is it considered a pollutant?
WARRIOR [948]

Carbon dioxide is a gas having chemical formula CO_{2}, a gas which exhaled by humans and inhaled by plants. It is also emitted from the sources such as cement production and combustion of fossil fuels. It is also known as greenhouse gas associated with acidification of ocean.

Carbon dioxide with other gases acts like a blanket of Earth which absorbs infrared radiations emitted from the sun and thus, preventing the escaping of these rays into the outer space which results in the gradual heating of Earth's surface and atmosphere i.e. increase in temperature of Earth. This process is known as Global Warming.

Hence, carbon dioxide is responsible for the increase in warming of the atmosphere i.e. option (D).



7 0
3 years ago
Read 2 more answers
Other questions:
  • I NEED HELP!
    13·2 answers
  • Write the net ionic equation for the reaction of barium chloride and sodium sulfate.
    12·1 answer
  • What type of graph, that isn't a bar graph, would be used to show 3 different classes choices of a favourite program and how eac
    10·1 answer
  • What is the pressure of a sample of gas at a volume of .335 L if it occupies 1700 mL at
    14·1 answer
  • The complex [Ni(CN)4]2- is diamagnetic and the complex [NiCl4]2- is paramagnetic. What can you conclude about their molecular ge
    15·1 answer
  • Which statement provides the best evidence that in environmental change can affect traits in later generations of an organisms p
    11·2 answers
  • What problems might there be if oxygen was very soluble in water?​
    5·1 answer
  • Equal masses of carbon dioxide (CO2) and oxygen (O2) are mixed. What is the mole
    13·1 answer
  • Which is not a characteristic of a compound?
    13·1 answer
  • In the laboratory, a student dilutes 18.9 ml of a 10.0 m perchloric acid solution to a total volume of 250.0 ml. what is the con
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!