Revising Covalent and Ionic Bonding

Which of the following substances has ionic bonds in it?

• iron(III) oxide, Fe₂O₃

• water, H₂O

• silicon oxide, SiO₂

• oxygen, O₂

Covalent bonding is responsible for holding the atoms together in which compound?

• sodium chloride, NaCl

• hydrogen chloride, HCl

• magnesium chloride, MgCl₂

• lead chloride, PbC_l2

The dashes in this diagram represent

• intermolecular forces

• ionic bonds

• covalent bonds

• magnetic forces

What does this diagram represent?

• macromolecule

• ionic lattice

• poly(ethene)

• sodium chloride

A substance made up of two or more atoms held together with covalent bonds is called a

• molecule

• compound

• hydrocarbon

• chemical

An electrostatic force between two oppositely charged ions is an _____ bond.

A ________ bond is a shared pair of electrons.

Simple covalent compounds often have low melting and boiling points because

• the intermolecular forces are weak

• a small number of covalent bonds

• covalent bonds are weaker than ionic bonds

• the electrons repel each other.

Ice floats on water. From this we can deduce that

• ice and water are chemically the same substance.

• ice and water contain different isotopes

• water is denser than ice

• 1g of ice weighs less than 1g of water