Question 1

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

Accepted Answer

Atomic number is the number of protons in an atom, while atomic mass is the sum of protons and neutrons.

Question 2

A neutral atom of carbon has an atomic number of 6 and an atomic mass of 12. How many neutrons does it have?

Accepted Answer

6

Question 3

Which of the following best explains why water is an excellent solvent for ionic compounds?

Accepted Answer

Water molecules form hydrogen bonds with ions, surrounding and separating them.

Question 4

Which property of water is primarily responsible for the ability of some insects to walk on its surface?

Accepted Answer

Cohesion due to hydrogen bonding

Question 5

If a solution has a hydrogen ion concentration of $$1 	imes 10$$^{-4}$$ M, what is its pH?

Accepted Answer

$$4$$

Question 6

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same atomic number but different atomic masses.

Question 7

Which of the following functional groups is correctly matched with its property?

Accepted Answer

Carboxyl group – hydrophilic

Question 8

Which type of bond is formed when two atoms share electrons unequally due to a difference in electronegativity?

Accepted Answer

Polar covalent bond

Question 9

Which of the following best describes a dehydration synthesis reaction?

Accepted Answer

A reaction that joins monomers to form polymers by removing water.

Question 10

Which of the following is a correct difference between RNA and DNA?

Accepted Answer

DNA contains deoxyribose sugar, while RNA contains ribose sugar.

Question 11

Which of the following best explains why saturated fatty acids are solid at room temperature while unsaturated fatty acids are liquid?

Accepted Answer

Saturated fatty acids have straight chains that pack tightly, while unsaturated fatty acids have kinks from double bonds that prevent tight packing.

Question 12

Which level of protein structure is directly determined by the sequence of amino acids?

Accepted Answer

Primary structure

Question 13

Which of the following statements about hydrogen bonds in water is correct?

Accepted Answer

Hydrogen bonds form between the hydrogen atom of one water molecule and the oxygen atom of another.

Question 14

A solution with a pH of 3 has how many times more hydrogen ions than a solution with a pH of 6?

Accepted Answer

1000 times

Question 15

Which of the following best describes the role of valence electrons in chemical bonding?

Accepted Answer

Valence electrons are shared or transferred between atoms to form chemical bonds.

Question 16

Which of the following is NOT a property of water that results from hydrogen bonding?

Accepted Answer

Nonpolarity

Question 17

Which of the following correctly matches a biological macromolecule with its monomer?

Accepted Answer

Carbohydrate – monosaccharide

Question 18

Which of the following best explains why phospholipids form bilayers in water?

Accepted Answer

Their hydrophobic tails avoid water while their hydrophilic heads interact with water.

Question 19

Which of the following bonds is responsible for maintaining the secondary structure of proteins?

Accepted Answer

Hydrogen bonds

Question 20

Which of the following statements about DNA and RNA is correct?

Accepted Answer

DNA stores genetic information, while RNA is involved in protein synthesis.

General Biology Study Notes: Chemical Context of Life & Molecular Diversity

Guida di studio - Domande di pratica