The most basic element is

• fluorine

• iodine

• chlorine

• bromine

Which one of the following transition metal ions is diamagnetic?

• Co²⁺

• Ni²⁺

• Cu²⁺

• Zn²⁺

Argon is used

• in filling airships

• to obtain low temperature

• in high temperature welding

• in radiotherapy for treatment of cancer

The metal that produces red-violet colour in the non-luminous flame is

• Ba

• Ag

• Rb

• Pb

Which of the following configurations corresponds to element of highest ionisation energy?

• 1s², 2s¹

• 1s², 2s², 2p³

• 1s², 2s², 2p²

• 1s², 2s², 2p⁶, 3s¹

246.

In long form of Periodic Table, the properties of the elements are a periodic function of their

• atomic size

• ionisation energy

• atomic mass

• atomic number

Which of the following is a wrong statement ? In a given period of the Periodic Table, the s-block element has, in general, a higher value of

• electronegativity

• atomic radius

• ionisation energy

• electron affinity

Which of the following is not correct ?

• Hydrolysis of NCl₃ gives NH₃ and HOCl

• NH₃ is less stable than PH₃

• NH₃ is a weak reducing reagent compared to PH₃

• Nitric oxide in solid state exhibits diamagnetic property

In III group precipitation, NH₄Cl is added before adding NH₄OH to

• decrease conc. of OH^-

• prevent interference of PO${}_4^{3-}$

• increase conc. of Cl^-

• increase conc. of OH^- ion

The most stable compound is

• LiF

• LiCl

• LiBr

• LiI