Question 1

If the half-life of a 4 gram sample of a radionuclide is 11 hours, then the half-life of a 2 gram sample of the same radionuclide would be

Accepted Answer

The half-life of a radionuclide does not depend on the amount of the sample, so the half-life of a 2 gram sample of the same radionuclide would be the same as the half-life of a 4 gram sample, which is 11 hours. Therefore, the correct answer is (B) 11.

Question 2

Which of the following would produce the most ion pairs as it interacts with matter?

Accepted Answer

Alpha particles are helium nuclei that carry a positive charge of +2. As they travel through matter, they collide with atoms, knocking off electrons and creating ion pairs. This means that alpha particles produce a large number of ion pairs as they interact with matter, making them highly ionizing.

Question 3

Which intermediate in the uranium-238 decay series constitutes the major source of radiation exposure for the average American?

Accepted Answer

Radon-222 is a radioactive gas that is produced from the decay of radium-226, which is an intermediate in the uranium-238 decay series. Radon-222 is a major source of radiation exposure for the average American because it can accumulate in homes and other buildings, and can be inhaled into the lungs. Inhaling radon gas increases the risk of lung cancer.

Question 4

The term nuclear energy is most closely associated with which one of the following processes?

Accepted Answer

Nuclear fission is the process in which the nucleus of an atom is split into smaller parts, releasing a large amount of energy. This is the process used in nuclear power plants to generate electricity. Nuclear fusion is the process in which two atomic nuclei combine to form a heavier nucleus, also releasing a large amount of energy. Radioactive decay is the natural process by which unstable atoms decay into more stable forms, releasing radiation in the process. Bombardment reactions involve the bombardment of atomic nuclei with particles such as protons or neutrons, leading to nuclear reactions.

Question 5

After 3 half-lives have elapsed, the amount of a radioactive sample that has not decayed is

Accepted Answer

After each half-life, the amount of a radioactive sample that has not decayed is halved. Therefore, after 3 half-lives, the amount remaining is (1/2)^3 = 1/8 of the original amount.

Question 6

The daughter isotope produced by the beta decay of  is

Accepted Answer

The beta decay of 11eaaed1_f3ac_6290_933a_8dec50aa97ab_TB5982_11 results in the conversion of a neutron to a proton, releasing an electron and an antineutrino. The daughter isotope will have one more proton and one less neutron than the parent isotope. Thus, the correct choice will have the same first 14 characters as the parent isotope (11eaaed1_f3ac_89a2_933a_ed4d6604a355_TB5982_11) with a different 15th-16th character due to the change in atomic number.

Question 7

The bombardment reaction involving  and  gives two products, one of which is  . The other product is

Accepted Answer

In this bombardment reaction, the first two molecules each donate a fluorine atom and form a bond. This leaves one molecule with an extra electron, which can then form a bond with the other molecule's extra electron. The result is two new molecules, one with a single bond between the two carbon atoms (11eaaed1_f3ac_d7c7_933a_e7514fcd3382_TB5982_11 ) and another with a double bond between the two carbon atoms and two extra fluorine atoms (11eaaed1_f3ac_feda_933a_d3bc6b50838b_TB5982_11 ). Therefore, the correct answer is C.

Question 8

The most recently produced synthetic elements have half-lives of the order of

Accepted Answer

The most recently produced synthetic elements have half-lives of the order of seconds, indicating that they are highly unstable and will decay quickly.

Question 9

Which of the following statement concerning the penetrating power into matter of various types of radiation is correct?

Accepted Answer

Gamma radiation has the highest penetrating power of all types of radiation and can penetrate deep layers of matter, while alpha and beta particles have a limited range of penetration, with alpha particles being the least penetrating. Therefore, D is the correct statement.

Question 10

Which of the following types of radiation is composed of particles with a charge and mass identical to that of an electron?

Accepted Answer

Alpha particles have a charge of +2 and mass of 4, gamma radiation is composed of photons with no charge or mass, and X-rays are a type of electromagnetic radiation with no charge or mass. Beta particles, on the other hand, are identical in charge and mass to electrons.

Question 11

The loss of an alpha particle by a radioactive nuclide causes

Accepted Answer

An alpha particle consists of 2 protons and 2 neutrons, so when a nuclide emits an alpha particle, its atomic number decreases by 2 (due to the loss of 2 protons) and its mass number decreases by 4 (due to the loss of 2 protons and 2 neutrons).

Question 12

If 6.00 grams of a 8.00 gram sample of a radioactive substance undergoes decay in 180 minutes, then the half-life of the substance is

Accepted Answer

To find the half-life of the substance, we can use the formula:

N = N₀(1/2)^(t/h)

where:
N₀ = initial amount of substance
N = amount of substance remaining after time t
h = half-life of substance

In this case, we know that:

N₀ = 8.00 g
N = 8.00 g - 6.00 g = 2.00 g (since 6.00 g of the substance has undergone decay)
t = 180 minutes

Plugging in these values, we get:

2.00 g = 8.00 g (1/2)^(180/h)

Simplifying, we get:

(1/2)^(180/h) = 0.25

Taking the logarithm of both sides (with base 1/2), we get:

180/h = log(0.25)/log(1/2)

180/h = 2

h = 90 minutes

Therefore, the half-life of the substance is 90 minutes, which is option B.

Question 13

Which of the following is not a balanced nuclear equation?

Accepted Answer

The answer of Which of the following is not a...

Question 14

Radioisotopes used in diagnostic medical procedures are usually

Accepted Answer

Gamma emitters are most commonly used in diagnostic medical procedures because they can easily penetrate the body's tissues and organs, allowing for imaging and diagnosis of various conditions. Alpha and beta emitters are less commonly used since they have a shorter range and are more harmful to the body. Using radionuclides with long half-lives would also not be ideal since they would remain in the body for longer periods of time, increasing the risk of radiation exposure.

Question 15

During a bombardment reaction, the particles colliding with target nuclei are

Accepted Answer

In a bombardment reaction, particles such as protons or alpha particles are accelerated to high velocities using a particle accelerator. These high-speed particles are small in size but have a lot of kinetic energy, allowing them to effectively collide with the target nuclei and induce nuclear reactions. Therefore, the best choice is A, as the particles are both small and traveling very fast.

Question 16

In terms of subatomic particles, the composition of an alpha particle is

Accepted Answer

An alpha particle is a helium nucleus and is composed of two neutrons and two protons.

Question 17

The explanation for how a beta particle is produced in the nucleus of a radionuclide and then ejected involves the conversion (in a complex series of steps) of a

Accepted Answer

The production of a beta particle involves the conversion of a neutron to a proton, which results in the emission of an electron as the beta particle. This process is called beta decay.

Question 18

Which of the following is the best definition for the term radionuclide?

Accepted Answer

A radionuclide is an atom whose nucleus is unstable and undergoes radioactive decay, releasing energy and particles in the process. This instability is caused by either having too many or too few neutrons in the nucleus, leading to an imbalance in the strong nuclear force that binds the nucleus together. Radionuclides are important in fields such as medicine, energy production, and nuclear weapons.

Question 19

Which of the following nuclear equations has an incorrect characterization?

Accepted Answer

The answer of Which of the following nuclear equations has...

Question 20

In which of the following pairs of chemical species are both members of the pair free radicals that are often produced by ionizing radiation?

Accepted Answer

H₂O⁺ and OH are both free radicals commonly produced by ionizing radiation, with unpaired electrons making them highly reactive.

Quiz 11: Nuclear Chemistry