Question

which property is characteristic of substances with metallic bonding due to the mobility of their electrons?
poor electrical conductivity
brittleness
low melting point
malleability and ductility
substances with ionic bonds typically exhibit which of the following properties?
low melting points
high electrical conductivity in the solid state
softness and low boiling points
brittleness and high melting points
what is the primary factor that determines whether a bond between two atoms will be predominantly ionic or covalent?

Explanation:

1. In metallic - bonded substances, the delocalized electrons allow for malleability and ductility. Poor electrical conductivity is incorrect as metals are good conductors. Brittleness is not a property related to metallic - bonding electrons' mobility. Low melting points are not characteristic of metals.
2. Ionic compounds typically have high melting points due to strong electrostatic forces between ions. They are brittle because of the arrangement of ions. In the solid state, they have low electrical conductivity as ions are not free to move. Softness and low boiling points are not typical of ionic compounds.

Answer:

1. Malleability and ductility
2. Brittleness and high melting points