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
natta225 [31]
3 years ago
7

As part of her nuclear stress test, Simone starts to walk on the treadmill. When she reaches the maximum level, Paul injects a r

adioactive dye with201Tl with an activity of 72 MBq . The radiation emitted from areas of her heart is detected by a scanner and produces images of her heart muscle. After Simone rests for 3 h, Paul injects more dye with 201Tl and she is placed under the scanner again. A second set of images of her heart muscle at rest is taken. When Simone's doctor reviews her scans, he assures her that she had normal blood flow to her heart muscle, both at rest and under stress.
Part A
If the half-life of 201Tl is 3.0 days, what is its activity, in megabecquerels after 3.0 days?
Express the activity to two significant figures and include the appropriate units.

Part B
What is its activity in megabecquerels after 6.0 days?
Express the activity to two significant figures and include the appropriate units.
Chemistry
1 answer:
Naya [18.7K]3 years ago
3 0

Answer:

Part A: 36 MBq; Part B: 18 MBq

Explanation:

The half-life is the time it takes for half the substance to disappear.

The activity decreases by half every half-life

A =Ao(½)^n, where n is the number of half-lives.

Part A

3.0 da = 1 half-life

A =  Ao(½) = ½ × 72 MBq = 36 MBq

Part B

6.0 da = 2 half-lives

A = Ao(½)^2 = ¼ × 72 MBq = 18 MBq

You might be interested in
Classify each of the statements below as pertaining to viscosity or osmolarity.
Yuliya22 [10]
Viscosity is related to the parallel shear force acted by the fluid. In lay man's term, viscosity is the ease of how the fluid flows. The faster the flow is, the lower the viscosity (and vice versa). On the other hand, osmolarity pertains to the concentration of a component in a mixture expressed in number of solute particles per liter of the mixture.
7 0
3 years ago
How does the formal charge play a role in resonance?
Crank
In a Lewis structure, formal charges can be assigned to each atom by treating each bond as if one-half of the electrons are assigned to each atom. ... Resonance occurs in cases where two or more Lewis structures with identical arrangements of atoms but different distributions of electrons can be written.
3 0
3 years ago
which of these solutions has the lowest freezing point? 0.25 m nacl 0.5 m nacl 1.0 m nacl 1.5 m nacl 2.0 m nacl
Alinara [238K]
The more particles (ions or molecules) that you can put into solution, the lower the freezing point. 

the answer is E. 2.0 M nacl
4 0
3 years ago
Read 2 more answers
__________ include(s) concussions and cuts or other damage to the spinal cord.
lukranit [14]
Nervous system injuries include concussions and cuts or other damage to the spinal cord. These injuries are usually caused by external impact to the body part extremely severed. They primarily comprise a diverse group of disorders that also affect the brain.
4 0
3 years ago
Use Dot and cross method to show the bonding of the atoms and state the number of atoms of each element present
goldfiish [28.3K]

Answer:

Check the attached one..I only draw the Dot method of Magnesium and Fluorine.. since i love chemistry ..Hope this helps you...Balance you have to do it yourself..If you didn't get the answer let me know in the comments..But you have try okay..

5 0
2 years ago
Other questions:
  • 2503(g) → 2502(g) O2(g)
    8·1 answer
  • Which group of elements have some properties of metals and some properties of nonmetals?
    15·1 answer
  • The hydrogen chloride (HCl) molecule has an internuclear separation of 127 pm (picometers). Assume the atomic isotopes that make
    9·1 answer
  • Science / which phrase describes the differences between these two liquid ?
    12·1 answer
  • as any personal information of clients, customers, employees, guests, or anyone else exposed in the incident?
    9·1 answer
  • Vapor obtained by evaporating 0.495 grams of an unknown liquid is collected in a 127 mL flask. At 371 K, the pressure of the vap
    5·1 answer
  • How can the rate of a reaction be increrased?
    5·1 answer
  • 1. As Z stays constant and the number of electrons increases, the electron-electron repulsions _____, and the anion becomes larg
    9·2 answers
  • Which phrase best describes humidity?
    12·2 answers
  • Is this the correct answer?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!