Inorganic Chemistry: 2026 Periodic Trends
Study Prep
Periodicity, Bonding, Coordination & Modern Inorganic Systems (100
Questions)
1. What is the fundamental definition of "Electronegativity"?
A) The energy required to remove an electron from an atom
B) The tendency of an atom to attract a shared pair of electrons in a chemical bond
C) The size of an atom's electron cloud
D) The number of valence electrons in an atom
Correct Answer: B) The tendency of an atom to attract a shared pair of electrons in a
chemical bond
2. Which trend describes the change in atomic radius moving from left to right across a
period?
A) It increases due to additional electron shells
B) It decreases due to increased effective nuclear charge pulling electrons closer
C) It remains constant
D) It fluctuates randomly
Correct Answer: B) It decreases due to increased effective nuclear charge pulling
electrons closer
3. "Ionization Energy" is defined as:
A) The energy released when an electron is added to an atom
B) The minimum energy required to remove the most loosely bound electron from an isolated
gaseous atom
C) The energy required to break a covalent bond
D) The energy of an electron in the ground state
Correct Answer: B) The minimum energy required to remove the most loosely bound
electron from an isolated gaseous atom
4. Why does the first ionization energy of Nitrogen (N) exceed that of Oxygen (O), despite
Oxygen's higher atomic number?
A) Oxygen is more electronegative
B) Nitrogen has a stable, half-filled $2p^3$ subshell, making it harder to remove an electron
C) Oxygen has a larger atomic radius
D) Nitrogen is a noble gas
, Correct Answer: B) Nitrogen has a stable, half-filled $2p^3$ subshell, making it harder to
remove an electron
5. "Electron Affinity" refers to:
A) The energy change when an electron is added to a gaseous atom
B) The ability to attract electrons in a bond
C) The size of the nucleus
D) The number of neutrons in an atom
Correct Answer: A) The energy change when an electron is added to a gaseous atom
6. Which group on the periodic table has the most negative (most exothermic) electron
affinity?
A) Alkali metals
B) Halogens (Group 17)
C) Noble gases
D) Alkaline earth metals
Correct Answer: B) Halogens (Group 17)
7. "Shielding Effect" (or screening effect) is caused by:
A) The nucleus repelling electrons
B) Inner-shell electrons reducing the pull of the nucleus on valence electrons
C) The magnetic field of the atom
D) The number of protons in the nucleus
Correct Answer: B) Inner-shell electrons reducing the pull of the nucleus on valence
electrons
8. In the context of "Effective Nuclear Charge" ($Z_{eff}$), what is the formula
approximation?
A) $Z_{eff} = Z - S$ (where $Z$ is atomic number, $S$ is shielding constant)
B) $Z_{eff} = Z + S$
C) $Z_{eff} = Z / S$
D) $Z_{eff} = Z * S$
Correct Answer: A) $Z_{eff} = Z - S$
9. Which element has the highest electronegativity according to the Pauling scale?
A) Oxygen
B) Nitrogen
C) Fluorine
D) Chlorine
Study Prep
Periodicity, Bonding, Coordination & Modern Inorganic Systems (100
Questions)
1. What is the fundamental definition of "Electronegativity"?
A) The energy required to remove an electron from an atom
B) The tendency of an atom to attract a shared pair of electrons in a chemical bond
C) The size of an atom's electron cloud
D) The number of valence electrons in an atom
Correct Answer: B) The tendency of an atom to attract a shared pair of electrons in a
chemical bond
2. Which trend describes the change in atomic radius moving from left to right across a
period?
A) It increases due to additional electron shells
B) It decreases due to increased effective nuclear charge pulling electrons closer
C) It remains constant
D) It fluctuates randomly
Correct Answer: B) It decreases due to increased effective nuclear charge pulling
electrons closer
3. "Ionization Energy" is defined as:
A) The energy released when an electron is added to an atom
B) The minimum energy required to remove the most loosely bound electron from an isolated
gaseous atom
C) The energy required to break a covalent bond
D) The energy of an electron in the ground state
Correct Answer: B) The minimum energy required to remove the most loosely bound
electron from an isolated gaseous atom
4. Why does the first ionization energy of Nitrogen (N) exceed that of Oxygen (O), despite
Oxygen's higher atomic number?
A) Oxygen is more electronegative
B) Nitrogen has a stable, half-filled $2p^3$ subshell, making it harder to remove an electron
C) Oxygen has a larger atomic radius
D) Nitrogen is a noble gas
, Correct Answer: B) Nitrogen has a stable, half-filled $2p^3$ subshell, making it harder to
remove an electron
5. "Electron Affinity" refers to:
A) The energy change when an electron is added to a gaseous atom
B) The ability to attract electrons in a bond
C) The size of the nucleus
D) The number of neutrons in an atom
Correct Answer: A) The energy change when an electron is added to a gaseous atom
6. Which group on the periodic table has the most negative (most exothermic) electron
affinity?
A) Alkali metals
B) Halogens (Group 17)
C) Noble gases
D) Alkaline earth metals
Correct Answer: B) Halogens (Group 17)
7. "Shielding Effect" (or screening effect) is caused by:
A) The nucleus repelling electrons
B) Inner-shell electrons reducing the pull of the nucleus on valence electrons
C) The magnetic field of the atom
D) The number of protons in the nucleus
Correct Answer: B) Inner-shell electrons reducing the pull of the nucleus on valence
electrons
8. In the context of "Effective Nuclear Charge" ($Z_{eff}$), what is the formula
approximation?
A) $Z_{eff} = Z - S$ (where $Z$ is atomic number, $S$ is shielding constant)
B) $Z_{eff} = Z + S$
C) $Z_{eff} = Z / S$
D) $Z_{eff} = Z * S$
Correct Answer: A) $Z_{eff} = Z - S$
9. Which element has the highest electronegativity according to the Pauling scale?
A) Oxygen
B) Nitrogen
C) Fluorine
D) Chlorine
