Elements which belong to the same group in the Periodic Table are characterized by

A. difference of +1 in the oxidation numbers of successive members

B. presence of the same number of outermost electrons in the respective atoms

C. difference of 14 atomic mass units between successive members

D. presence of the same number of electron shells in the respective atoms

The atom of an element X combines with aluminium (₁₃AI)?

A. AIX ₂

B. AI ₂X

C. AI₂X ₂

D. AI ₂X ₃

The presence of unpaired electrons in an atom of a transition metal gives rise to

A. paramagnetism

B. nalleability

C. ductility

D. shiny appearance

What is responsible for metallic bonding?

A. Sharing of electrons between the metal atoms

B. Attraction between the atomic unclei and cloud of electrons

C. transfer of electrons from one atom to another

D. Attraction between positive and negative ions

Which of the following compounds is covalent?

A. CaCI₂

B. MgO

C. NaN

D. CH₄

A sheet of paper is placed in the path of a beam from a radioactive source. The emissions that pass through the paper consist of

A. alpha particles and gamma rays

B. alpha and beta particles

C. beta particles and gamma rays

D. alpha particles only

Which of the following features of a human skeleton can be determined by carbon-dating?

A. Height

B. Mass

C. Age

D. Race

Which of the following statements about ideal gases is/are correct? 1. The cohesive forces between their particles are negligible ll. The have no definite volume but occupy the volume of their containers III. They are not compressible IV. Their particles collide with loss of energy

A. l only

B. l and ll only

C. l, ll and lll only

D. l, ll, lll, and IV

P _Total = F₁ + P₂ + P ₃ + .........P_n' where P _Total is the pressure of a mixture of gasses. The equation above is an expression of

A. Graham's law

B. Gay-Lussac's Law

C. Boyle's law

D. Dalton's law

Which of the following pairs of reagents reat to produce hydrogen?

A. Zinc and concentrated trioxonitrate (V) acid

B. Water and calcium dicarbide

C. Copper and dilute hydrochloric acid

D. Magnesium and dilute tetraoxosulphate (VI) acid

A mixture of calcium chloride and calcium trioxocarbonate (IV) in water can be separated by

A. evaporation

B. sublimation

C. distillation

D. filtration