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
Anastaziya [24]
4 years ago
5

Use the library and other reference materials to research the discovery of radioactivity and its current applications. Then, wri

te a 500 word report on what you have learned. Be sure to include the contributions of French chemists Marie Curie and Pierre Curie and the medical uses of radiation.
Chemistry
1 answer:
Dafna1 [17]4 years ago
8 0

Henri Becquerel was a French physicist who in 1896 discovered a new property of matter (which was later called radioactivity). This was accidentally observed when Becquerel found out that uranium salt was spontaneously emitting some kind of rays that went through different substances and were able to veil even a photographic film.  Then Marie Curie and her husband Pierre Curie carried out more experiments to study, in a quantitative way, the radiation emitted by the salts Becquerel studied cualitatively, and other salts that contained uranium. During this process they found other radioactive substances, such as: thorium, polonium and radium.These radioactive isotopes have proven particularly effective as tracers in certain diagnostic procedures. As radioisotopes are identical chemically with stable isotopes of the same element, they can take the place of the latter in physiological processes. Moreover, because of their radioactivity, they can be readily traced even in minute quantities with such detection devices as gamma-ray spectrometers and proportional counters. Though many radioisotopes are used as tracers, iodine-131, phosphorus-32, and technetium-99m are among the most important. Physicians employ iodine-131 to determine cardiac output, plasma volume, and fat metabolism and particularly to measure the activity of the thyroid gland where this isotope accumulates. Phosphorus-32 is useful in the identification of malignant tumours because cancerous cells tend to accumulate phosphates more than normal cells do. Technetium-99m, used with radiographic scanning devices, is valuable for studying the anatomic structure of organs.

pls give me branliest

You might be interested in
Describe the reasoning behind using phosphorus and boron in conjunction<br> with one another.
Assoli18 [71]

defective greatest formerly knows sd ghost;

4 0
2 years ago
_______________ are filled with special absorbing elements that move up and down between the uranium rods to keep the atoms from
d1i1m1o1n [39]

Answer:

The correct answer is - control rods.

Explanation:

Control rods are filled with special absorbing agents such as boron, cadmium, silver, and others to absorb as many neutrons as to control the fission reaction by moving them up and down in between uranium rods.

These control rods are used to prevent the nuclear reaction from getting out of control in the nuclear plant or reactor by absorbing the neutrons and prevent uranium to convert.

8 0
3 years ago
Match the following aqueous solutions with the appropriate letter from the column on the right. Assume complete dissociation of
Serhud [2]

Answer:  0.17 m CH_3COONH_4 : Highest freezing point

0.20 m CoSO_4: Second lowest freezing point

0.18 m MnSO_4: Third lowest freezing point

0.42 m ethylene glycol: Lowest freezing point

Explanation:

Depression in freezing point  is a colligative property which depend upon the amount of the solute.

\Delta T_f=i\times k_f\times m

where,

\Delta T_f = change in freezing point

i= vant hoff factor

k_f = freezing point constant

m = molality

a) 0.17 m CH_3COONH_4

For electrolytes undergoing complete dissociation, vant hoff factor is equal to the number of ions it produce. Thus i =2 for CH_3COONH_4, thus total concentration will be 0.34 m

b) 0.18 m MnSO_4

For electrolytes undergoing complete dissociation, vant hoff factor is equal to the number of ions it produce. Thus i = 2 for MnSO_4, thus total concentration will be 0.36 m

c) 0.20 m CoSO_4

For electrolytes undergoing complete dissociation, vant hoff factor is equal to the number of ions it produce. Thus i = 2 for CoSO_4, thus total concentration will be 0.40 m

d) 0.42 m ethylene glycol

For non electrolytes undergoing no dissociation, vant hoff factor is equal to 1 . Thus i = 1 for ethylene glycol, thus concentration will be 0.42 m

The more is the concentration, the highest will be depression in freezing point and thus lowest will be freezing point.

4 0
3 years ago
The Al2O3 crystal structure (corundum) consists of an HCP arrangement of O2- ions; the Al3+ ions occupy octahedral positions. Wh
vesna_86 [32]

Answer:

The fraction of the available octahedral positions are filled with Al^{3+} ions is \frac{2}{3}

Explanation:

If there are n numbers of spheres in HCP in packing:

Number of octahedral void = n

Number of tetrahedral void = 2n

Total number of voids = n + 2n = 3n

The Al_2O_3 crystal structure consists of an HCP arrangement of O^{2-}ions.

Number of spheres in HCP = 6

Number of O^{2-} = 6

Number of octahedral voids = 6

Number of tetrahedral void = 12

Number of aluminum ions when there are 6 O^{2-} ion =\frac{2}{3}\times 6= 4

Number of voids in which Al^3+ ions are present = 4

The fraction of the available octahedral positions are filled with Al^{3+} ions = \frac{4}{6}=\frac{2}{3}

5 0
4 years ago
In a _________ reaction, the mass of the reactants is equal to the mass of the products. Select all that apply.
Shalnov [3]
Chemical reaction. Law of equal masses
3 0
3 years ago
Read 2 more answers
Other questions:
  • 255070 meters converted to centimeters. <br> Express your answer in 6 significant figures
    8·1 answer
  • The veterinarian prescribes the NSAID carprofen for a 50-pound dog with arthritis at a dose of 4.4 mg/kg and would like this dos
    10·1 answer
  • The bond between molecules of a gas is _____. <br><br> none <br> weak <br> moderate <br> strong
    12·1 answer
  • For which of these elements would the first ionization energy of the atom be higher than that of the diatomic molecule? helium o
    12·2 answers
  • Which sample contains a total of 6.0 x 1023 particles?
    7·1 answer
  • A sealed container at 25oC contains a gas at a pressure of 104 kPa. What is the pressure of the gas when it is heated to 225oC?
    11·1 answer
  • Why does waters boiling point decrease with increases in elevation
    6·2 answers
  • Draw an energy diagram showing the process involved in the production of an absorption spectrum. Use this diagram to help you co
    15·1 answer
  • The chemical formula for sodium citrate is Nag Cs H5O7
    11·1 answer
  • A 5.00 L flask at 25˚ C contains 0.200 mol of Cl2 . What is the pressure in the flask?
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!