Atomic and ionic radii

27 questions on Atomic and ionic radii from the Periodic Table and Periodicity chapter: 5 NEET level, 12 JEE Main, 10 JEE Advanced. Each one opens with its answer and solution.

• The radius of the sodium cation Na+ is smaller than that of the sodium atom mainly because: NEET level
• The chloride ion Cl- is larger than the chlorine atom because: NEET level
• Which of the following represents the correct increasing order of atomic radii? NEET level
• Which of the following species has the largest radius? NEET level
• Among the second-period elements Li, B, N and F, the one with the smallest atomic radius is: NEET level
• The correct increasing order of ionic radii for the isoelectronic ions O^2-, F-, Na+ and Mg^2+ is: JEE Main level
• Which pair of elements has almost identical atomic radii as a direct result of the lanthanoid contraction? JEE Main level
• In solid chlorine the Cl-Cl distance within a molecule is 199 pm, while the shortest distance between chlorine atoms of two neighbouring molecules is 332 pm. Th... JEE Main level
• The correct decreasing order of radii of Fe, Fe^2+ and Fe^3+ is: JEE Main level
• The metallic radius of aluminium is 143 pm and that of gallium is 135 pm, although gallium lies one period below. This is best explained by: JEE Main level
• The quoted radius of neon (160 pm) is much larger than that of fluorine (64 pm), even though neon has a higher nuclear charge. The reason is that: JEE Main level
• The ionic radius of Na+ is reported as 99 pm (coordination number 4), 102 pm (CN 6) and 118 pm (CN 8). This shows that: JEE Main level
• The correct decreasing order of ionic radii for V^2+, V^3+, V^4+ and V^5+ is: JEE Main level
• Which statement correctly describes a consequence of the lanthanoid contraction? JEE Main level
• The ions S^2-, Cl-, K+ and Ca^2+ all have the configuration (1s)^2(2s,2p)^8(3s,3p)^6 and Slater Z^* values (for a 3p electron) of 4.75, 5.75, 7.75 and 8.75 resp... JEE Main level
• Consider the species N^3-, O^2-, F-, Na+, Mg^2+ and Al^3+. Which statements are correct? JEE Main level
• Which comparisons of an ion with its parent atom are correct? JEE Main level
• The 6-coordinate radii (in pm) of some trivalent ions are Dy^3+ 91.2, Ho^3+ 90.1, Er^3+ 89.0, Lu^3+ 86.1 and Y^3+ 90.0. Yttrium therefore most closely resembles... JEE Advanced level
• Four ions W, X, Y and Z are the ions O^2-, F-, Na+ and Mg^2+ in some order. Their 6-coordinate radii are W 72 pm, X 140 pm, Y 102 pm and Z 133 pm. The sum of th... JEE Advanced level
• The Si-Si bond length in silicon is 235 pm and the Cl-Cl bond length in chlorine is 199 pm. The simple additive covalent radii predict an Si-Cl bond length of 2... JEE Advanced level
• In crystalline iodine the I-I bond length is 267 pm and the shortest contact between iodine atoms of different molecules is 354 pm. Taking the van der Waals rad... JEE Advanced level
• Ionic potential is defined as phi = z/r (charge over radius in pm). Radii (6-coordinate, pm): Be^2+ 45, Li+ 76, Mg^2+ 72, Ca^2+ 100 and Al^3+ 53.5. Which ion ha... JEE Advanced level
• The metallic radii of Group 13 are Ga 135 pm, In 167 pm and Tl 170 pm. The increase from Ga to In is 32 pm but from In to Tl only 3 pm. The most appropriate exp... JEE Advanced level
• The increasing order of radii of Sn^4+, Pb^4+, Sn^2+ and Pb^2+ is: JEE Advanced level
• Which statements about the lanthanoid contraction and its effects are correct? JEE Advanced level
• Which statements about the different types of atomic and ionic radii are correct? JEE Advanced level
• The ions S^2-, Cl-, K+ and Ca^2+ are isoelectronic with Slater Z^* values (3p electron) of 4.75, 5.75, 7.75 and 8.75 respectively. With radius assumed proportio... JEE Advanced level