Classification of Elements and Periodicity in Properties

Which of the following statements about the interstitial compounds is incorrect?

• They retain metallic conductivity

• They are chemically reactive

• They are much harder than the pure metal

• They have higher melting points than the pure metal

In Periodic Table, the basic character of oxides

• increases from left to right and decreases from top to bottom

• decreases from right to left and increases from top to bottom

• decreases from left to right and increases from top to bottom

• decreases from left to right and increases from bottom to top

In haemoglobin, the metal ion present is

• Fe²⁺

• Zn²⁺

• Co²⁺

• Cu²⁺

Which of the following orders regarding ionisation energy is correct?

• N > O > F

• N < O < F

• N > O < F

• N < O < F

Identify [A] and [B] in the following

${}_{89}{}^{227}\mathrm{Ac} \stackrel{-\mathrm{\beta }}{\to } \left[\mathrm{A}\right] \stackrel{-\mathrm{\alpha }}{\to } \left[\mathrm{B}\right] \stackrel{-\mathrm{\alpha }}{\to } \mathrm{Rn}$

• Po, Rn

• Th, Po

• Ra, Th

• Th, Ra

The electronic configuration 1s², 2s²2p⁶, 3s²3p⁶3d⁹ represents a

• metal atom

• non metal atom

• non-metallic anion

• metallic cation

In a given shell the order of screening effect is

• s > p > d > f

• s > p > f > d

• f > d > p > s

• s < p < d < f

Identify the least stable ion amongst the following.

• Li^-

• Be^-

• B^-

• C^-

The ionisation energy of hydrogen atom is 13.6eV. What will be the ionisation energy of He⁺?

• 13.6 eV

• 54.4 eV

• 122.4 eV

• Zero

Which element has highest electronegativity ?

• F

• He

• Ne

• Na