Periodic Table Quiz

The first ionization energy generally increases across a period in the Periodic Table. Which statement explains why the first ionization energy of sulphur is lower than that of phosphorus?

• 
  The electrons in the p orbitals of sulphur experience greater electrostatic repulsion than that of phosphorus.

• The sulphur atom has more electrons than phosphorus atom

• The S-S bond is weaker than P-P bond.

• The size of S8 molecule is bigger than P4 molecule.

Answer explanation

The electronic configuration of sulphur is [Ne]3s² 3p⁴

The paired 3p electrons occupying the same region in space experience electrostatic repulsion. This makes the electrons easier to remove.

Elements X,Y and Z are located in Period 3 of the Periodic Table. The reactivity of these elements towards oxygen is shown in the table below. The arrangement of the elements according to the ascending order of their proton number is

• X,Y,Z

• X,Z,Y

• Z,X,Y

• Z,Y,X

Which oxide of an element dissolves in water to form an acidic solution?

• Sodium

• Magnesium

• Silicon

• Phosphorus

The electronic configuration of element X is [Xe]4f75d16s2. Which is element X located in the Periodic Table?

• Period 4
  Block s

• Period 5
  Block p

• Period 6
  Block s

• Period 6
  Block f

Answer explanation

The outermost orbital occupied by electron is 6s.

Therefore, X is in Period 6

X has incompletely filled f orbitals.

X is an f-block element.

Which oxides of magnesium, silicon and chlorine correspond correctly to their acid-base property?

• MgO - Base

  SiO2 - Base

  Cl2O7 - Acid

• MgO - Base

  SiO2 - Acid

  Cl2O7 - Acid

• MgO - Base

  SiO2 - Neutral

  Cl2O7 - Neutral

• MgO - Neutral

  SiO2 - Neutral

  Cl2O7 Acid

Answer explanation

MgO is an ionic oxide. It has basic.

SiO₂ and Cl₂O₇ are covalent oxides. They are acidic.

Which element has an oxide which dissolves in water to form an acidic solution?

• Al

• Na

• P

• Si

The properties of elements can be deduced from electronic configurations. Which statement is true about Na+ ion, Cl- ion, Ar atom and K+ ion?

• Na+ ion is bigger than Cl- ion.

• The charge density of Na+ ion is lower than that of Cl- ion.

• The ionization energy of K+ ion is higher than that of Na+ ion.

• Cl- ion, K+ ion and Ar atom have the same electronic configuration.

Which oxide will produce 1.0 moldm-3 aqueous solution with the lowest pH value?

• Na2O

• MgO

• P2O5

• SO3

The first ionisation energies of five elements in Period 2 of the Periodic Table is shown in the graph below.

Which statement explains the difference in the first ionization energies between beryllium and boron?

• Boron atom has more valence electrons.

• Boron atom has a greater shielding effect

• Beryllium atom has a more stable electronic configuration.

• The 2p electron in boron atom is at a higher energy level than the 2s electron in beryllium atom.

Answer explanation

Both beryllium and boron have 2 inner shell electrons.

The electronic configuration of Be is 1s² 2s². The 2s² configuration has higher stability than expected. This causes the first IE of Be to be higher than expected.

The acid-base property of oxides are related to their structure and chemical bonding. Which oxide dissolved in water to form an acidic solution?

• MgO

• Al2O3

• SiO2

• SO3