Question 1

Which of the following is used to image the liver?

Accepted Answer

(⁹⁹Tc) is used to image the liver as it utilizes a radioactive agent called Technetium-99m, which is taken up by liver cells and can provide detailed images of the liver's internal structure and function.

Question 2

Suppose you have two very sensitive balances that can measure the masses of individual particles, depicted below. In these figures, "p" corresponds to a proton, and "n" corresponds to a neutron.   What is the relationship between the mass readings of the two balances? (Neglect differences due to experimental uncertainty.)

Accepted Answer

The answer of Suppose you have two very sensitive balances...

Question 3

Which of the following is used to image the brain?

Accepted Answer

Magnetic Resonance Imaging (MRI) is used to image the brain, and option C has the MRI code (¹²³I).

Question 4

What material is ionized by radiation in a Geiger counter?

Accepted Answer

Geiger counters use Argon gas, among other gases, which gets ionized by radiation, allowing the device to detect and measure ionizing radiation levels.

Question 5

In the following diagrams, A represents a radioactive isotope that decays into a new isotope, X. Each circle represents 1 mmol of atoms. t = 0:  t = 25.0 s:  Which diagram best represents the sample at t = 50.0 s?

Accepted Answer

At t=25.0 s, half of the sample has decayed into the new isotope X, leaving 0.5 mmol of A and 0.5 mmol of X. At t=50.0 s, another half of the remaining A will decay, leaving only 0.25 mmol of A and 0.75 mmol of X. The only diagram that represents this ratio of A to X is option C.

Question 6

Which of the following is used to test the activity of the thyroid?

Accepted Answer

(¹³¹I) is used to test the activity of the thyroid.

Question 7

Nuclei with an ________ number of protons and an ________ number of neutrons tend to be more stable than those with an ________ number of protons and/or an ________ number of neutrons.

Accepted Answer

Nuclei with an even number of both protons and neutrons tend to be more stable due to the attractive forces between particles that occur in pairs (proton-proton, neutron-neutron, and proton-neutron). This is known as the "even-even effect". In contrast, nuclei with an odd number of protons and/or neutrons have unpaired particles, which can lead to instability and decay.

Question 8

Which of the following type(s) of radiation is/are detected by a Geiger counter?

Accepted Answer

Geiger counters are designed to detect ionizing radiation, which includes alpha particles, beta particles, and gamma rays. These types of radiation ionize atoms in the Geiger counter's tube, triggering a measurable electrical pulse.

Question 9

Which of the following is injected into the bloodstream to trace the flow of blood and detect possible constrictions or obstructions in the circulatory system?

Accepted Answer

The answer of Which of the following is injected into...

Question 10

In order to investigate the age of a mineral sample believed to be millions of years old, which would be the best choice of radioactive isotope to measure?

Accepted Answer

The answer of In order to investigate the age of...

Question 11

What is the nuclear process called in which a heavy nuclear of mass number greater than 200 divides to form smaller nuclei of intermediate mass and one or more neutron(s)?

Accepted Answer

The nuclear process described is nuclear fission, in which a heavy nucleus of mass number greater than 200 (such as uranium-235) splits into smaller nuclei of intermediate mass (such as krypton-92 and barium-141) and one or more neutrons.

Question 12

Which of the following isotopes is least likely to be stable?

Accepted Answer

Isotopes with a large imbalance between protons and neutrons are generally less stable. Aluminum-30 has a significant imbalance, making it less stable compared to the other isotopes listed.

Question 13

How old is the oldest object that can reliably be dated using ¹⁴C dating?

Accepted Answer

¹⁴C dating, also known as radiocarbon dating, can reliably date objects up to around 60,000 years old. Beyond this point, the amount of carbon-14 remaining in the object is too small to accurately measure. Therefore, the oldest object that can reliably be dated using ¹⁴C dating is approximately 60,000 years old.

Question 14

In the following diagrams, A represents a radioactive isotope that decays into a new isotope, X. Each circle represents 1 mmol of atoms. t = 0:  t = 25.0 s:  Over the first 25.0 s, what is the disintegration rate of A?

Accepted Answer

The disintegration rate of A can be determined by calculating the difference in the number of A atoms between t = 0 and t = 25.0 s, and dividing by the time interval of 25.0 s.

At t = 0, the number of A atoms is 1 mmol, or 6.02 x 10^20 atoms (since 1 mmol equals Avogadro's number, 6.02 x 10^23, of atoms).
At t = 25.0 s, the number of A atoms has decreased to approximately 0.5 mmol, or 3.01 x 10^20 atoms, while the number of X atoms has increased to approximately 0.5 mmol, or 3.01 x 10^20 atoms.

The difference in the number of A atoms between t = 0 and t = 25.0 s is therefore:

6.02 x 10^20 - 3.01 x 10^20 = 3.01 x 10^20

The disintegration rate of A is equal to this difference divided by the time interval of 25.0 s:

(3.01 x 10^20) / 25.0 = 1.20 x 10^19 disintegrations per second

This value is equivalent to 7.23 x 10^19 disintegrations per minute, or approximately 1.20 disintegrations per second. Therefore, the best choice is D.

Question 15

What is the total binding energy of ¹²C? [¹²C atomic mass = 12.000 amu; mass of proton = 1.007825 amu; mass of neutron = 1.008665 amu; 1 kg = 6.022 x 10²⁶amu; 1 J = 1 (kg•m²)/s²]?

Accepted Answer

The total binding energy can be calculated by first determining the mass defect, which is the difference between the mass of the unbound nucleons and the actual mass of the nucleus. For carbon-12 (C-12), which has 6 protons and 6 neutrons, the mass of the unbound nucleons would be $6 \times 1.007825 \, \text{amu} + 6 \times 1.008665 \, \text{amu}$. The atomic mass of C-12 is given as 12.000 amu. Subtracting the atomic mass of C-12 from the total mass of the unbound nucleons gives the mass defect. This mass defect is then converted to energy using Einstein's equation $E=mc^2$, where $m$ is the mass defect in kilograms and $c$ is the speed of light in meters per second. The energy obtained is in joules. The correct calculation leads to an answer in the order of magnitude of $10^{-12}$ to $10^{-11}$ joules, which corresponds to the option that is closest to typical binding energy values for a nucleus of this size.

Question 16

Which of the following is used to image the heart?

Accepted Answer

Technetium-99m (99mTc) is commonly used in nuclear medicine for imaging the heart, particularly in myocardial perfusion scans.

Question 17

In the following diagrams, A represents a radioactive isotope that decays into a new isotope, X. Each circle represents 1 mmol of atoms. t = 0:  t = 25.0 s:  What is the half-life of A?

Accepted Answer

The answer of In the following diagrams, A represents a...

Question 18

Most nuclear reactors in the United States are ________.

Accepted Answer

According to the US Nuclear Regulatory Commission, more than 90% of nuclear reactors in the United States are light water reactors, which use regular water as a coolant and neutron moderator.

Question 19

Why is carbon dating possible?

Accepted Answer

Carbon dating is possible because there is a constant ratio of C-12 to C-14 in living organisms, but the ratio changes at a predictable rate after an organism dies. This allows scientists to determine the age of once-living materials, such as fossils or archaeological artifacts, by measuring the amount of C-14 remaining in the sample.

Question 20

Which of the following best represents the relationship between the energy released (ΔE) and the mass defect (Δm)?

Accepted Answer

The answer of Which of the following best represents the...

Quiz 20: Nuclear Chemistry

Which of the following is used to image the liver?

Which of the following is used to image the brain?

What material is ionized by radiation in a Geiger counter?

In the following diagrams, A represents a radioactive isotope that decays into a new isotope, X. Each circle represents 1 mmol of atoms. t = 0: t = 25.0 s: Which diagram best represents the sample at t = 50.0 s?

Which of the following is used to test the activity of the thyroid?

Nuclei with an number of protons and an number of neutrons tend to be more stable than those with an number of protons and/or an number of neutrons.

Which of the following type(s) of radiation is/are detected by a Geiger counter?

Which of the following is injected into the bloodstream to trace the flow of blood and detect possible constrictions or obstructions in the circulatory system?

In order to investigate the age of a mineral sample believed to be millions of years old, which would be the best choice of radioactive isotope to measure?

What is the nuclear process called in which a heavy nuclear of mass number greater than 200 divides to form smaller nuclei of intermediate mass and one or more neutron(s) ?

Which of the following isotopes is least likely to be stable?

How old is the oldest object that can reliably be dated using ¹⁴C dating?

In the following diagrams, A represents a radioactive isotope that decays into a new isotope, X. Each circle represents 1 mmol of atoms. t = 0: t = 25.0 s: Over the first 25.0 s, what is the disintegration rate of A?

What is the total binding energy of ¹²C? [¹²C atomic mass = 12.000 amu; mass of proton = 1.007825 amu; mass of neutron = 1.008665 amu; 1 kg = 6.022 x 10²⁶amu; 1 J = 1 (kg•m²) /s²]?

Which of the following is used to image the heart?

In the following diagrams, A represents a radioactive isotope that decays into a new isotope, X. Each circle represents 1 mmol of atoms. t = 0: t = 25.0 s: What is the half-life of A?

Most nuclear reactors in the United States are ________.

Why is carbon dating possible?

Which of the following best represents the relationship between the energy released (ΔE) and the mass defect (Δm) ?

Quiz 20: Nuclear Chemistry

Which of the following is used to image the liver?

Which of the following is used to image the brain?

What material is ionized by radiation in a Geiger counter?

In the following diagrams, A represents a radioactive isotope that decays into a new isotope, X. Each circle represents 1 mmol of atoms. t = 0: t = 25.0 s: Which diagram best represents the sample at t = 50.0 s?

Which of the following is used to test the activity of the thyroid?

Nuclei with an ________ number of protons and an ________ number of neutrons tend to be more stable than those with an ________ number of protons and/or an ________ number of neutrons.

Which of the following type(s) of radiation is/are detected by a Geiger counter?

Which of the following is injected into the bloodstream to trace the flow of blood and detect possible constrictions or obstructions in the circulatory system?

In order to investigate the age of a mineral sample believed to be millions of years old, which would be the best choice of radioactive isotope to measure?

What is the nuclear process called in which a heavy nuclear of mass number greater than 200 divides to form smaller nuclei of intermediate mass and one or more neutron(s) ?

Which of the following isotopes is least likely to be stable?

How old is the oldest object that can reliably be dated using 14C dating?

In the following diagrams, A represents a radioactive isotope that decays into a new isotope, X. Each circle represents 1 mmol of atoms. t = 0: t = 25.0 s: Over the first 25.0 s, what is the disintegration rate of A?

What is the total binding energy of 12C? [12C atomic mass = 12.000 amu; mass of proton = 1.007825 amu; mass of neutron = 1.008665 amu; 1 kg = 6.022 x 1026 amu; 1 J = 1 (kg•m2) /s2]?

Which of the following is used to image the heart?

In the following diagrams, A represents a radioactive isotope that decays into a new isotope, X. Each circle represents 1 mmol of atoms. t = 0: t = 25.0 s: What is the half-life of A?

Most nuclear reactors in the United States are ________.

Why is carbon dating possible?

Which of the following best represents the relationship between the energy released (ΔE) and the mass defect (Δm) ?

Nuclei with an number of protons and an number of neutrons tend to be more stable than those with an number of protons and/or an number of neutrons.

How old is the oldest object that can reliably be dated using ¹⁴C dating?

What is the total binding energy of ¹²C? [¹²C atomic mass = 12.000 amu; mass of proton = 1.007825 amu; mass of neutron = 1.008665 amu; 1 kg = 6.022 x 10²⁶amu; 1 J = 1 (kg•m²) /s²]?