Question

K forms the compound K2O , which is an ionic compound that is brittle. Identify another element, M , that is likely to form a brittle, ionic compound with the formula M2O . Justify your answer in terms of periodic trends.

Answer 1

Na₂O will also form a brittle ionic compound

Answer 2

Explanation is given below.

Explanation:

• The opposite element is Sodium.
• The given compound contains formula $\[{{K}_{2}}O\]$.
• The oxidation number of potassium is +1.
• The group showing oxidation number as +1 is Group 1. Elements which belong to Group 1 are generally metals.
• The oxidation number of elements belonging to same group have same number of valence electrons and thus shows same number.

Properties shown by metals:

• They are hard.
• They are solid at room temperature.
• They show lustrous property.
• They are ductile and malleable.

         

• But, there are some exceptions. Sodium and potassium belonging to Group 1 are brittle in nature.
• They can be easily cut with knife.
• The compound having formula $\[{{M}_{2}}O\]$, during which oxidation number of metal is +1 and is brittle in nature.
• Hence, the opposite element are going to be sodium.