Question

Which of the following provides a characteristic of

MgO(s) with a correct explanation?
Choose 1 answer:
А
It is hard because its ions are held together by strong
electrostatic attractions.
B
It is malleable because its atoms can easily move past
one another without disrupting the bonding.
It is a poor conductor of electricity because its
electrons are tightly held within covalent bonds and
lone pairs.
It has a high melting point because its molecules
interact through strong intermolecular forces.

Answer 1

MgO is hard because it is composed of magnesium and oxygen ions held together by strong electrostatic attractions in an ionic bond, resulting in a crystal lattice that provides significant hardness and a high melting point.

Step-by-step explanation:

The correct answer to the question is that magnesium oxide (MgO) is hard because its ions are held together by strong electrostatic attractions. Magnesium oxide is an ionic compound, meaning it is made up of magnesium ions (Mg2+) and oxygen ions (O2-) that are held together by ionic bonds. These ionic bonds arise from the transfer of electrons from magnesium to oxygen, leading to the formation of cations and anions which are strongly attracted to each other in a crystal lattice.

Due to the strong ionic bonds in the MgO lattice, the compound exhibits characteristic hardness and a high melting point. These properties are typical of ionic compounds and are not consistent with substances that have malleable features or those held together by weaker intermolecular forces such as in covalent molecular compounds.

Therefore, the explanation for the characteristic hardness of MgO is related to the strong electrostatic forces between the oppositely charged ions within its crystalline structure.

Answer 2

А It is hard because its ions are held together by strong electrostatic attractions.

B It is malleable because its atoms can easily move past one another without disrupting the bonding.

Step-by-step explanation:

These are correct explanations of the properties of magnesium.

C is wrong. Mg is a good conductor of electricity and it has metallic bonds.

D is wrong. Mg has no molecules. It has no intermolecular forces.