Chapter 3: Structure of Bonding

What is ionic bonding?

Ionic bonding is the electrostatic attraction between positive and negative ions.

How are ionic compounds held together?

Ionic compounds are held together in a giant lattice structure.

State a property of ionic substances based on their structure.

Ionic substances have high melting and boiling points due to strong electrostatic forces.

Why do ionic compounds not conduct electricity when solid?

Ionic compounds do not conduct electricity when solid because the ions are in fixed positions.

What allows ionic compounds to conduct electricity when molten or dissolved?

Ions are free to move when ionic compounds are molten or dissolved.

What is the importance of charge balance in ionic compounds?

Ionic compounds must be electrically neutral, meaning positive and negative charges balance each other.

How are ionic compounds formed?

Ionic compounds are formed by the transfer of electrons from a metal to a non-metal.

What happens to magnesium and oxygen to form MgO?

Magnesium loses 2 electrons to become Mg2+, and oxygen accepts 2 electrons to become O2-.

What is a covalent bond?

A covalent bond is a shared pair of electrons between two atoms.

Describe the properties of simple molecular covalent substances.

They do not conduct electricity, consist of small molecules, and have low melting and boiling points.

How do intermolecular forces change with the size of the molecule?

Intermolecular forces increase with the mass/size of the molecule.

What are polymers?

Polymers are very large molecules with atoms linked by covalent bonds.

What are thermosoftening polymers?

Thermosoftening polymers are types of polymers that melt or soften when heated.

What are giant covalent substances?

Giant covalent substances are solids where atoms are covalently bonded in a giant lattice.

Give an example of a giant covalent substance.

Examples include diamond, graphite, and silicon dioxide.

Describe the structure of diamond.

Diamond has four strong covalent bonds for each carbon atom, making it very hard.

What is metallic bonding?

Metallic bonding is the attraction between delocalised electrons and the nuclei of metal ions.

List two properties of metals.

Metals have high melting/boiling points and are good conductors of heat and electricity.

What are alloys?

Alloys are mixtures of metals with other elements.

Why are alloys harder than pure metals?

Different sizes of atoms in alloys distort the layers, preventing them from sliding easily.

What does the energy needed to change state depend on?

It depends on the strength of forces between the particles of the substance.

What is the melting point of a pure substance?

A pure substance will melt or boil at a fixed temperature.

What are nanoparticles and their specific use?

Nanoparticles have a high surface area to volume ratio and are used in various applications like medicine.

What are the sizes of fine and coarse particles?

Fine particles have a diameter of 100-2500 nm, while coarse particles range from 2500-10000 nm.

Why do nanoparticles have different properties than bulk materials?

Nanoparticles have different properties due to their high surface area to volume ratio.