Practice questions on how elements are named using their atomic numbers according to IUPAC nomenclature rules for clarity in chemical communication.
Second ionization enthalpy is highest for Li (removing e⁻ from Li+ with 1s²) and decreases across period 2 as stability reduces: Li > Be > B > C.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Nomenclature of Elements with Atomic Number >100
First ionization enthalpy decreases down a group due to increasing size. Among O, S, Se, and Te, Te (period 5) has the lowest value.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Nomenclature of Elements with Atomic Number >100
Electronegativity decreases down group 15. N (period 2, 3.0) has the highest value among N, P, As, and Sb.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Nomenclature of Elements with Atomic Number >100
Chalcogens are group 16 elements. Te (group 16) is a chalcogen, while As (group 15), Br (group 17), and Ge (group 14) are not.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Nomenclature of Elements with Atomic Number >100
The fifth period (n=5) includes 5s (2 electrons), 4d (10 electrons), and 5p (6 electrons), totaling 18 electrons.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Nomenclature of Elements with Atomic Number >100
Bond energy in XO₂ decreases down group 14 due to weaker orbital overlap. CO₂ (C=O) has the highest bond energy compared to SiO₂, GeO₂, or SnO₂.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Nomenclature of Elements with Atomic Number >100
For Z=115: 1 (un), 1 (un), 5 (pent) → ununpentium (before being named Moscovium).
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Nomenclature of Elements with Atomic Number >100
For Z = 115: 1 (un), 1 (un), 5 (pent) → ununpentium (before its official name, Moscovium).
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Nomenclature of Elements with Atomic Number >100
All group 15 elements can exhibit a +5 oxidation state, but N achieves it most prominently (e.g., in HNO₃) due to its small size and high electronegativity, unlike P, As, or Sb.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Nomenclature of Elements with Atomic Number >100
Pnictogens are group 15 elements. Sb (group 15) is a pnictogen, while Te (group 16), I (group 17), and Sn (group 14) are not.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Nomenclature of Elements with Atomic Number >100
In group 15, As is a metalloid, while N (non-metal), P (non-metal), and Bi (metal) are not.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Nomenclature of Elements with Atomic Number >100
Second period elements (Li to F) have only 2s and 2p orbitals, limiting covalency to 4. C (group 14) achieves this (e.g., CH₄), unlike Li, Be, or N.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Nomenclature of Elements with Atomic Number >100
