$$40 \times \left(\frac{1}{2}\$$right)^3$$ = 5 g$$

$$8.0 \times \left(\frac{1}{2}\$$right)^3$$ = 1.0$$ mCi

Question 1

Which subatomic particle is responsible for the unique identity of an element, and where is it located within the atom?

Accepted Answer

Proton; in the nucleus

Question 2

Given an atom with atomic number 17 and mass number 37, how many neutrons does it contain?

Accepted Answer

$$37 - 17 = 20$$ neutrons

Question 3

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons

Question 4

A radioactive isotope decays by emitting a beta particle. Which of the following nuclear equations correctly represents this process for carbon-14?

Accepted Answer

$$^{14}_{6}\mathrm{C} \$$rightarrow ^{14}$$_{7}\mathrm{N} $$+ ^{0}$$_{-1}\beta$$

Question 5

Which form of radiation has the greatest penetrating power and requires thick lead or concrete for shielding?

Accepted Answer

Gamma ($$\gamma) $$rays

Question 6

If a sample of a radioisotope has a half-life of 3 days, how much of a 40 g sample remains after 9 days?

Accepted Answer

$$40 	imes \left(\frac{1}{2}\$$right)^3$$ = 5 g$$

Question 7

Which unit is used to measure the biological effect of radiation on tissue?

Accepted Answer

Sievert (Sv)

Question 8

A patient is injected with 8.0 mCi of a radioisotope with a half-life of 6 hours. How much activity remains after 18 hours?

Accepted Answer

$$8.0 	imes \left(\frac{1}{2}\$$right)^3$$ = 1.0$$ mCi

Question 9

Which of the following is a real-life medical application of technetium-99m ($$^{99m}\mathrm{Tc}$$)?

Accepted Answer

Diagnosis of blood flow in the lungs

Question 10

What is the charge and mass number of an alpha particle?

Accepted Answer

Charge $$+2$$, mass number $$4$$

Question 11

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes have the same atomic number but different mass numbers

Question 12

A PET scan uses a radioisotope that emits positrons. What happens when a positron meets an electron in the body?

Accepted Answer

A gamma ray is produced

Question 13

Which of the following best describes the difference between atomic mass and mass number?

Accepted Answer

Atomic mass is the weighted average of all isotopes; mass number is the sum of protons and neutrons

Question 14

Which of the following nuclear equations represents the production of a radioisotope by neutron bombardment?

Accepted Answer

$$^{98}_{42}\mathrm{Mo} $$+ ^{1}$$_{0}\mathrm{n} \$$rightarrow ^{99}$$_{42}\mathrm{Mo}$$

Question 15

Which of the following is a common misconception about the biological effects of alpha particles?

Accepted Answer

Alpha particles can penetrate deep into the body and cause widespread damage

Question 16

A patient receives a dose of 120,000 mrem of radiation. According to the clinical effects table, what is the most likely outcome?

Accepted Answer

Light radiation poisoning with delayed symptoms

Question 17

Which of the following statements about the structure of an atom is correct?

Accepted Answer

Most of the atom consists of empty space

Question 18

Which radioisotope is commonly used for the treatment of thyroid cancer?

Accepted Answer

Iodine-131 ($$^{131}\mathrm{I})$$

Atoms, Isotopes, and Radioactivity: Foundations for GOB Chemistry

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