Question 1

Which of the following statements best explains why large atomic nuclei are more likely to be radioactive than small nuclei?

Accepted Answer

Large nuclei require a higher neutron-to-proton ratio to remain stable, and if this ratio is not maintained, the nucleus becomes unstable and radioactive.

Question 2

A radioactive isotope of phosphorus, $$^{32}_{15}P$$, undergoes beta decay. What is the nuclear equation for this process?

Accepted Answer

$$^{32}_{15}P \$$rightarrow ^{32}$$_{16}S $$+ ^{0}$$_{-1}e$$

Question 3

Which type of radiation has the highest ionizing power but the lowest penetrating power?

Accepted Answer

Alpha ($$\alpha) $$radiation

Question 4

A hospital uses $$^{131}I to $$diagnose thyroid disorders. Which property of $$^{131}I$$ makes it suitable for this purpose?

Accepted Answer

It emits radiation that can be detected externally and is selectively absorbed by the thyroid gland.

Question 5

If a sample of a radioactive isotope has a half-life of 4 days, what fraction of the original sample remains after 12 days?

Accepted Answer

$$\frac{1}{8}$$

Question 6

Which of the following best describes the process of nuclear fission?

Accepted Answer

A large nucleus splits into two smaller nuclei, releasing energy and additional neutrons.

Question 7

Which of the following is a correct statement about the structure and function of phospholipids in cell membranes?

Accepted Answer

Phospholipids have polar heads that face outward toward water and nonpolar tails that face inward, forming a bilayer.

Question 8

Which of the following best explains why humans cannot digest cellulose?

Accepted Answer

Humans lack the enzymes necessary to break the specific glycosidic bonds in cellulose.

Question 9

A triglyceride is formed by the reaction of which of the following components?

Accepted Answer

One glycerol and three fatty acids

Question 10

Which of the following statements about protein structure is correct?

Accepted Answer

The primary structure of a protein is the sequence of amino acids held together by peptide bonds.

Question 11

Which of the following best describes the difference between DNA and RNA?

Accepted Answer

DNA contains deoxyribose sugar and the base thymine, while RNA contains ribose sugar and the base uracil.

Question 12

During protein synthesis, what is the role of mRNA?

Accepted Answer

It carries the genetic code from DNA in the nucleus to the ribosome for translation.

Question 13

Which of the following is a correct nuclear equation for the alpha decay of $$^{226}_{88}Ra$$?

Accepted Answer

$$^{226}_{88}Ra \$$rightarrow ^{222}$$_{86}Rn $$+ ^{4}$$_{2}He$$

Question 14

A patient receives a dose of gamma radiation for cancer treatment. Which property of gamma rays makes them suitable for this purpose?

Accepted Answer

Gamma rays have high penetrating power, allowing them to reach and destroy cancer cells deep within tissues.

Question 15

Which of the following best describes the function of enzymes in biological systems?

Accepted Answer

They act as biological catalysts, speeding up chemical reactions necessary for life.

Question 16

Which of the following statements about saturated and unsaturated fats is correct?

Accepted Answer

Saturated fats are solid at room temperature and have no carbon-carbon double bonds.

Question 17

Which of the following best describes the process of DNA replication?

Accepted Answer

The DNA double helix unwinds, hydrogen bonds break, and each strand serves as a template for the formation of a new complementary strand.

Question 18

Which of the following is a function of cholesterol in the human body?

Accepted Answer

It is a component of cell membranes and a precursor for steroid hormones.

Question 19

Which of the following best explains why a diet high in saturated fats increases the risk of heart disease?

Accepted Answer

Saturated fats can lead to artery blockages, increasing the risk of heart attacks and strokes.

Radioactivity, Nuclear Chemistry, and Biomolecules: Study Notes for Introductory Chemistry

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