The letters X, Y and Z represent different atoms and their nuclear symbol notations are listed in the image on the left.

Which statements about atoms X, Y and Z are correct?          

I.        X and Y have same number of electrons.

II.       X and Z have same number of neutrons.

III.      Y and Z have same number of protons.

• I and II only

• I and III only

• II and III only

• I, II and III

The formula for gallium phosphate is GaPO₄. What is the correct formula for gallium sulfide?

• Ga₂(SO₄)₃

• Ga₂(SO₃)₃

• Ga₂(SO₂)₃

• Ga₂S₃

Which statement(s) concerning the atomic structure and the periodic table is/are correct?

I. An element in group 4 has 4 valence electrons.

II. An ion from period 2 will have a charge of 2+.

III. An element in group 2 has 2 energy levels.

• I only

• II only

• II and III only

• I, II and III

Which properties about isotopes of elements are correct? 

I.      They have same electron configuration.

II.    They have same mass number.

III.   They have different physical properties.

• I and II only

• I and III only

• II and III only

• I, II and III

Which combination of characteristics of element M, a metal, and element N, a non-metal, is most likely to lead to ionic bonding?

• 
• 
• 
• 

Which series is arranged in the order of increasing reactivity?

• F < Cl < Br

• O < S < Se

• Be < Mg < Ca

• Li < Na < K

Which compounds have an ionic lattice structure in the solid state? 

I. Diphosphorus trioxide

II. Magnesium fluoride

III. Ammonium carbonate

• I and II only

• I and III only

• II and III only

• I, II and III

Which compound will have the lowest melting point?

• Na₂O

• MgO

• Al₂O₃

• P₄O₁₀

Which substance will not conduct electricity in its molten state?

• carbon tetrachloride

• magnesium iodide

• lead(II) bromide

• sodium chloride

Which compound contains only ionic bonding?

• potassium carbonate

• aluminum nitrate

• sodium bromide

• ammonium chloride