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

Answer:

Na₂O will also form a brittle ionic compound.

Explanation:

Sodium is located in the same group as Potassium: Alkali Metals. This is because both elements have similar chemical properties. In term of their electronegativity, both elements are very close. Na has an electronegativity of 0.93, while K has an electronegativity of 0.82. This makes both ideal elements to create ionic compounds with Oxygen.

Answer 2

Answer: The other element is Sodium.

Explanation:

We are given a chemical compound having formula $K_2O$

The oxidation state of potassium is +1. The group showing oxidation state as +1 is Group 1. Elements belonging to Group 1 are metals.

The oxidation state of elements belonging to same group have same number of valence electrons and thus shows same oxidation state.

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 chemical compound having formula $M_2O$, in which oxidation state of metal is +1 and is brittle in nature.

Hence, the other element will be sodium