For the process ,

X (g) + e^- $\to$ X^- (g) ; $\mathrm{\Delta }$H = x

and X^- (g) $\to$ X (g) + e^- ; $\mathrm{\Delta }$H = y

select correct alternate

• Ionisation energy of x^- (g) is y

• Electron affinity of X (g) is x

• Electron affinity of X (g) is - y

• All of the above

Which of the following reactions does not take place?

BF₃ + F^- $\to$B${\mathrm{F}}_4^{-}$          ...(I)

BF₃ + 3F^- $\to$B${\mathrm{F}}_6^{3-}$       ...(II)

AlF₃ + 3F^- $\to$ Al${\mathrm{F}}_6^{3-}$    ...(III)

• Only (I)

• Only (II)

• Only (III)

• Only (I) and (III)

An element (X) belongs to fourth period and fifteenth group of the periodic table. Which one of the following is true regarding the outer electronic configuration of (X)? It has

• partially filled d orbitals and completely filled s orbital

• completely filled s orbital and completely filled p orbitals

• completely filled s orbital and half-filled p orbitals

• half-filled d orbitals and completely filled s orbital.

Which of the following is a favourable factor for cation formation ?

• Low ionisation potential

• High electron affinity

• High electronegativity

• Small atomic size

Assertion : Generally alkali and alkaline earth metals form superoxides.

Reason: There is a single bond between O and O in superoxides.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion : For hydrogen like species, energy of an electron in a particular orbit increases with increase in value of Z.

Reason : Electronegativity decreases across a period.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false

In a group of Periodic Table what is the basis of :

• ionic potential

• electron affinity

• electron negativity

• number of covalent electron

The correct electronic configuration of element with atomic number 29 :

• 1s² , 2s² 2p⁶ , 3s² 3p⁶ 3d¹⁰ , 4s¹

• 1s² , 2s² 2p⁶ , 3s² 3p⁶ 3d¹¹

• 1s² , 2s² 2p⁶ , 3s² 3p¹⁷

• None of the above

The correct size ofiodine atom and iodine ion is :

• I^- > I⁺ > I

• I > I⁺ > I^-

• I > I^- > I⁺

• I⁺ > I > I^-

460.

The pair of amphoteric hydroxides is

• Be(OH)₂, Al(OH)₃

• Al(OH)₃, LiOH

• B(OH)₃, Be(OH)₂

• Be(OH)₂, Mg(OH)₂