The atoms of four elements are represented as ₂₀Q, ₁₆R, ₁₀S and ₈T Which of the elements would be unreactive?

A. Q

B. R

C. S

D. T

Chlorine atom forms CI by

A. losing one electron

B. Sharing one electron

C. Donating lone pair of electrons

D. Gaining one electron

An element Z has a combining power of 3. Which of the following formulae is correct of its compounds?

A. ZSO₃

B. Z₃CI₂

C. Z ₂O ₃

D. ZS₃

Electrovalent compounds are characterized by

A. solubility in ethanol

B. high molar mass

C. high melting point

D. strong oxidizing ability

The type of chemical bond that exists between potassium and oxygen in potassium oxide is

A. ionic

B. metallic

C. covalent

D. dative

Which of the following contains co-ordinate covalent bond?

A. HCI

B. CH ₄

C. NH₄

D. Na⁺CI

Elactrostatic force of attraction between sodium ion and halide ion is greatest in

A. NaCI

B. NaBr

C. NaF

D. NaI

Which of the following non-metals reacts most readily with metals?

A. Nitrogen

B. Chlorine

C. Sulphur

D. Carbon

A radioactive solid is best stored

A. under paraffin oil

B. under ultraviolet light

C. in a cool, dark cupboard

D. in a box lined with lead