D425 SCIE 2030
Introduction to Chemistry
OA READINESS EXAM GUIDE
Q&S
©2024/2025
,1. Which of the following is the most abundant element in the
human body?
a) Carbon
b) Oxygen
c) Hydrogen
d) Nitrogen
Answer: b) Oxygen
Rationale: Oxygen is the most abundant element, making up
about 65% of the human body by weight.
2. What type of bond is primarily responsible for the secondary
structure of proteins?
a) Ionic bonds
b) Hydrogen bonds
c) Covalent bonds
d) Van der Waals forces
Answer: b) Hydrogen bonds
Rationale: Hydrogen bonds stabilize the secondary structure,
particularly the alpha helices and beta sheets in proteins.
3. In an exergonic chemical reaction, the products have...
a) More energy than the reactants
b) Less energy than the reactants
c) The same amount of energy as the reactants
d) It depends on the reaction type
Answer: b) Less energy than the reactants
Rationale: Exergonic reactions release energy, meaning the
products have lower energy than the reactants.
4. Which of the following elements is most likely to form a
cation?
©2024/2025
, a) Neon
b) Helium
c) Sodium
d) Chlorine
Answer: c) Sodium
Rationale: Sodium tends to lose one electron to form a cation
with a positive charge (Na+).
5. Which of the following is an example of a polar covalent
bond?
a) H2
b) N2
c) H2O
d) O2
Answer: c) H2O
Rationale: Water (H2O) has polar covalent bonds due to the
difference in electronegativity between hydrogen and oxygen.
### Fill-in-the-Blank
6. The degree to which a substance can dissolve in water is
referred to as its ________.
Answer: solubility
Rationale: Solubility refers to the extent to which a substance
can dissolve in a solvent, particularly water.
7. The specific heat capacity of water is _______ J/g°C.
Answer: 4.18
Rationale: Water has a high specific heat capacity of 4.18
Joules per gram per degree Celsius, aiding in temperature
regulation.
8. Hydrogen bonds are particularly important in stabilizing the
©2024/2025
Introduction to Chemistry
OA READINESS EXAM GUIDE
Q&S
©2024/2025
,1. Which of the following is the most abundant element in the
human body?
a) Carbon
b) Oxygen
c) Hydrogen
d) Nitrogen
Answer: b) Oxygen
Rationale: Oxygen is the most abundant element, making up
about 65% of the human body by weight.
2. What type of bond is primarily responsible for the secondary
structure of proteins?
a) Ionic bonds
b) Hydrogen bonds
c) Covalent bonds
d) Van der Waals forces
Answer: b) Hydrogen bonds
Rationale: Hydrogen bonds stabilize the secondary structure,
particularly the alpha helices and beta sheets in proteins.
3. In an exergonic chemical reaction, the products have...
a) More energy than the reactants
b) Less energy than the reactants
c) The same amount of energy as the reactants
d) It depends on the reaction type
Answer: b) Less energy than the reactants
Rationale: Exergonic reactions release energy, meaning the
products have lower energy than the reactants.
4. Which of the following elements is most likely to form a
cation?
©2024/2025
, a) Neon
b) Helium
c) Sodium
d) Chlorine
Answer: c) Sodium
Rationale: Sodium tends to lose one electron to form a cation
with a positive charge (Na+).
5. Which of the following is an example of a polar covalent
bond?
a) H2
b) N2
c) H2O
d) O2
Answer: c) H2O
Rationale: Water (H2O) has polar covalent bonds due to the
difference in electronegativity between hydrogen and oxygen.
### Fill-in-the-Blank
6. The degree to which a substance can dissolve in water is
referred to as its ________.
Answer: solubility
Rationale: Solubility refers to the extent to which a substance
can dissolve in a solvent, particularly water.
7. The specific heat capacity of water is _______ J/g°C.
Answer: 4.18
Rationale: Water has a high specific heat capacity of 4.18
Joules per gram per degree Celsius, aiding in temperature
regulation.
8. Hydrogen bonds are particularly important in stabilizing the
©2024/2025
