answer.
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
kvv77 [185]
2 years ago
8

Three radioisotopes are being discussed in a chemistry class. Technetium-99m has a half-life of 6 hours. Rubidium-87 has a half-

life of 50 billion years. Which describes who would most likely use each isotope? A geologist would use technetium-99m because short-life indicates an older organism, and a doctor would use rubidium-87 because it allows for a more-accurate measurement of disease.
A doctor would use technetium-99m because a short half-life indicates a quick measurement, and a geologist would use rubidium-87 because a longer half-life means that there is a longer time to measure old rock.
A doctor would use technetium-99m because a short half-life indicates a quick measurement, and an archeologist would use rubidium-87 because anything containing carbon also contains rubidium.
A geologist would use technetium-99m because a short half-life indicates an older organism, and an archeologist would use rubidium-87 because anything containing carbon also contains rubidium.
Chemistry
2 answers:
prohojiy [21]2 years ago
4 0

Answer:

A doctor would use technetium-99m because a short half-life indicates a quick measurement, and a geologist would use rubidium-87 because a longer half-life means that there is a longer time to measure old rock.

Explanation:

The radioisotopes are used to measure the presence of certain elements in molecules and in different substances, Technetium-99m has a short time of half life, 6 hours is good for doctors to measure the presence of that element in the human body or in another organisms, in the case of geologists, Rubidium-87, and its presence in certain rocks can make an impact on the presence and age of those rocks.

suter [353]2 years ago
3 0
B.)<span>A doctor would use technetium-99m because a short half-life indicates a quick measurement, and a geologist would use rubidium-87 because a longer half-life means that there is a longer time to measure old rock. </span>
You might be interested in
Reacting 35.4 ml of 0.220 m agno3 with 52.0 ml of 0.420 m k2cro4 results in what mass of solid formed
laila [671]
Answer is: 1.29 grams <span>of solid formed.
</span>Chemical reaction: 2AgNO₃(aq) + K₂CrO₄(aq) → Ag₂CrO₄(s) + 2KNO₃(aq).
n(AgNO₃) = c(AgNO₃) · V(AgNO₃).
n(AgNO₃) = 0.220 M · 0.0351 L.
n(AgNO₃) = 0.0078 mol; limiting reactant.
n(K₂CrO₄) = 0.420 M · 0.052 L.
n(K₂CrO₄) = 0.022 mol.
From chemical reaction: n(AgNO₃) : n(Ag₂CrO₄) = 2 : 1.
n(Ag₂CrO₄) = 0.0078 mol ÷ 2.
n(Ag₂CrO₄) = 0.0039 mol.
m(Ag₂CrO₄) = 0.0039 mol · 331.73 g/mol.
m(Ag₂CrO₄) = 1.29 g.

7 0
2 years ago
Type the correct answer in the box. Express the answer to three significant figures.
frutty [35]

Answer : The energy released is -3319.7 KJ.

Solution : Given,

Mass of methane = 59.7 g

Molar mass of methane = 16 g/mole

\Delta H=-890KJ/mole

The value of \Delta H is in negative that means the energy is releasing.

First we have to calculate the moles of methane.

Moles of methane = \frac{\text{ Mass of methane}}{\text{ Molar mass of methane}}= \frac{59.7g}{16g/mole}=3.73moles

Now we have to calculate the amount of energy released.

The given reaction is,

CH_4+2O_2\rightarrow CO_2+2H_2O

From the reaction, we conclude that

1 mole of methane releases -890 KJ/mole of energy

3.73 moles of methane releases \frac{-890KJ/mole}{1mole}\times 3.73mole=-3319.7KJ of energy

Therefore, the energy released is -3319.7 KJ.

5 0
2 years ago
If the kinetic energy of a particle is equal to twice its rest mass, what is the velocity of the particle? Determine if relativi
ivann1987 [24]

Answer:

The velocity of the particle is 2 m/s,

Explanation:

Kinetic energy is defined as energy of the body due to its motion. It is given by :

K.E=\frac{1}{2}mv^2

Where :

m = mass of the object

v = velocity of the object

We have , particle with mass m and its kinetic energy is twice its mass.

K.E=2m

2m=\frac{1}{2}mv^2

v^2=\frac{4}{1}

v=2

And unit of velocity are m/s , so the velocity of the particle is 2 m/s.

8 0
2 years ago
What is the name of the functional group that is attached to this hydrocarbon? The first and last of a chain of three carbons ar
disa [49]

Answer:

Ketone

Explanation:

As you are stating here, we have a carbonated chain of three carbons, and the first and last has 3 Hydrogens, then this means that we have CH₃ . The center carbon is a carbon double bonded to oxygen.

In general terms this belongs to the carbonyl group. However, this alone does not represent a functional group, but when it's in a chain with other radycals or chains, it becomes a functional group.

In this case, the molecule you are talking here is the following:

CH₃ - CO - CH₃

This molecule is known as the Acetone, and has the general form of:

R - CO - R'

Which belongs to a ketone as a functional group.

4 0
2 years ago
25. In the investigation shown the changes in heat of the copper is greater than the change in the heat of the water. What error
forsale [732]

Answer:

Heat lost to the surroundings

Heat lost to the thermometer

Explanation:

All changes in heat, or energy, can be explained. Many of the reactions or changes we see in the world involve the conversion of energy. For example as we heat up a substance (eg. water), the amount of energy we put in should give us an exact temperature. However, this is a "perfect world" scenario, and does not occur in real life. Whenever heat is added to a substance like water, we always need to account for the energy that is going to be lost. For example, heat lost to evaporation or even the effect of measuring the temperature with a thermometer (the introduction of anything including a thermometer will affect the temperature).

3 0
2 years ago
Other questions:
  • Carbon dioxide dissolves in water to form carbonic acid. this acid lowers the ph of the water and makes the water corrosive. wha
    12·1 answer
  • Instrumental methods need only a microscopic sample to return an accurate result. Why is this so?
    7·1 answer
  • A piece of metal with a mass of 611 g is placed into a graduated cylinder that contains 25.1 ml of water, raising the water leve
    8·1 answer
  • Which image exclusively represents the principle of radiation? A) IV B) III C) II D) I
    8·2 answers
  • 1. For HF and HBr, the partial positive charge on H atom is 0.29 and 0.09, respectively. Use electronegativities (EN) to explain
    15·1 answer
  • A diver is going through ocean search-and-rescue training. The graph shows the relationship between her depth and the time in se
    13·1 answer
  • A student has two samples of NaCl, each one from a different source. Assume that the only potential contaminant in each sample i
    9·1 answer
  • Copper atoms are heavier than magnesium atoms. So, although each atom of magnesium can produce one atom of copper, the masses wo
    13·1 answer
  • Hypothesis and Observations
    13·1 answer
  • Compound X has a molar mass of 104.01·gmol−1 and the following composition: element mass % nitrogen 26.93% fluorine 73.07% Write
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!