Bonding and structures

Which of the following explains why the giant ionic lattice structure of sodium chloride causes the crystals to have high melting point?

• The oppositely charged ions are arranged closely together.

• The oppositely charged ions are arranged in an orderly and regular manner.

• The oppositely charged ions are held by strong electrostatic forces of attraction.

A chemical bond can be made by the _______ of valence electron(s) by an atom when it reacts with other atom(s).

• sharing

• lost

• gaining

Which particles are responsible for conduction of electricity in graphite? (TYS Qn)

• electrons only

• electrons and positive ions

• negative and positive ions

• negative ions only

Which property is common to both diamond and graphite? (TYS Qn)

• Each atom in the structure forms four covalent bonds.

• They act as lubricant.

• They are electrical insulators.

• They are insoluble in water and organic solvents

Which pair of elements combine together to form an ionic compound? (modified TYS Qn)

• aluminium and oxygen

• carbon and sulfur

• chlorine and oxygen

• oxygen and sulfur

Which of the following is true about graphite?

• It has weak intermolecular forces of attraction between layers of carbon atoms.

• It can conduct electricity.

• It has a low melting point.

• It has strong covalent bonds between carbon atoms

The dot-and-cross diagram of ethane is shown. What is true about the substance?

• It is very soluble in water.

• It is able to conduct electricity when molten.

• It has strong electrostatic forces of attraction.

• It has low melting and boiling point.

Oxygen crystals are obtained by freezing oxygen at -223^oC. What will the crystals contain? (TYS Qn)

• oxygen atoms and molecules

• oxygen ions and oxygen atoms

• oxygen molecules only

• oxygen atoms only

Which type of structures have the following properties?

1) high melting points

2) able to conduct electricity in aqueous and molten states only

3) soluble in water, insoluble in organic solvents

• giant metallic structures

• simple molecular structures

• giant covalent structures

• giant ionic lattice structures

Carbon disulfide, CS₂, is a covalent liquid at room temperature. Which statement explains why it is a liquid at room temperature. (modified TYS Qn)

• It has strong covalent bonds between atoms.

• It has weak intermolecular forces of attraction between molecules.

• It has strong electrostatic forces of attraction between oppositely charged ions.

• It has strong electrostatic forces of attraction between positive ions and surrounding sea of delocalized electrons.