2.1 Chemical bonds and types of bonding

What are compounds in chemistry?

Substances in which 2 or more elements are chemically combined.

What are the three types of chemical bonding?

Ionic, covalent, and metallic.

What is ionic bonding?

Particles are oppositely charged ions, typically formed between metals and non-metals.

What is covalent bonding?

Atoms share pairs of electrons, occurs in most non-metallic elements and in compounds of non-metals

what is metallic bonding?

Particles are atoms which share delocalised electrons, Occurs in metallic elements and alloys

What happens to metal atoms in ionic bonding?

They lose electrons in outside shell transfer to the non-metal atom to become positively charged ions.

What do non-metal atoms do in ionic bonding?

They gain electrons from the metal atom to become negatively charged ions.

What is an ion?

An atom that has lost or gained electron(s).

What is an Ionic compound?

• A giant structure of ions

• held together by strong electrostatic forces of attraction between oppositely charged ions

• Since the structure is in 3D, the forces act in every direction

Give an example of an ionic compound.

Sodium chloride (NaCl). Na+ and Cl-

What is Covalent bonding?

• Covalent bonding is when atoms share one or more pairs of electrons..

● Small molecules, such as: HCl, H2, O2, Cl2, NH3, CH4 have strong covalent bonds within their molecules.

● Polymers are large covalently bonded molecules.

● Giant covalent structures (macromolecules) consist of many atoms covalently bonded in a lattice structure. For example: diamond, silicon dioxide.

● Diagrams to show these substances could be dot and cross, shown as repeat units for polymers using a single line to represent a single bond, ball and stick and two and three-dimensional diagrams.

What are giant covalent structures?

Structures consisting of many atoms covalently bonded in a lattice structure, such as diamond.

What are polymers in the context of covalent bonding?

Large covalently bonded molecules.

What does the delocalised electron system in metals consist of?

Electrons lost from the atoms to form positive ions.

What do metallic bonds allow the structure of metals to do?

They allow delocalised electrons to move freely, contributing to the metal's strength.

What is Metallic bonding?

● The bonding in a metal consists of positive ions (atoms that have lost electron(s))

and delocalised electrons arranged in a regular pattern.

● The delocalised electron system consists of the electrons ‘lost’ from the atoms to

form positive ions.

● Delocalised electrons are free to move through the structure.

● The delocalised electrons are shared through the structure so metallic bonds are

strong.