Structure and Bonding


State of Matter

- partciles in a solid are packed closely together, vibrate around fixed positions

- particles in a liquid are also close toegher but they can slip and slide over each other

- particles in a gas have lots of space between them and move around randomly

- in melting and boiling, energy is transferred from surroundings to substance

- in freezing and condensing, enrgy is transferred from the substance to the surroundings

1 of 12

Atoms into Ions

- elements can react together to form compounds by gaining or losing electrons or by sharing electrons

- the elements in gorup 1 react with group 7, as they react atoms of group 1 elements can each lose one electron to gain stable electronic structure of noble gas

- this electron can be given to an atom from group 7, which then also achieves the stable electronic structure of a noble gas

2 of 12

Ionic Bonding

- ionic compounds are held together by strong forces of attraction between their oppositely charged ions

- besides the elements in group 1 and 7, other elements that can form ionic compounds include:

   those from group 2 (forming 2+ ions)

   and group 6 (forming 2- ions)

3 of 12

Giant Ionic Structure

- takes alot of energy to break the many strong ionic bonds, operating in all directions, that hold a giant ionic lattice together

- ionic compounds have high melting points, they are all solids at room temperature

- ionic compounds will conduct electricity when molten or dissolved in wter, this is because their ions can then become mobiole and can carry charge through the liquid

4 of 12

Covalent Bonding

- covalent bonds are formed when atoms of non-metals share pairs of electrons with each other 

- each shared pair of electrons is a covalent bond

- many substances containing covalent bonds consist of simple molecules but some have giant covalent structures

5 of 12

Structure of Simple Molecules

- substances made up of simple molecules have low melting and boiling points

- the forces between simple molecules are weak, these weak intermolecular forces explain why substances made up of simple molecules have low melting and boiling points

- simple molecules have no overall charge, so they can't carry electrical charge, therefore, substances made of simple molecules do not conduct electricity

- molecules are used to help understand bonding but each model has its limitations in representing reality

6 of 12

Giant Covalent Structures

- some covalently-bonded substances have giant structures, these substances have very high melting and boiling points

- graphite contains giant layers of covalently bonded carbon atoms, however, there are no covalent bonds between the layers, meaning they can slide over each other, making graphite soft and slippery

- the carbon atoms in diamond have a rigid giant covalent structure, making it a very hard substance

- graphite can conduct electricity and thermal energy because of the delocalised electrons that can move along it's layers

7 of 12

Fullerenes and Graphene

- as well as diamond and graphite, carbon also exists as fullerenes, which can form alrge cage-like structures and tubes, based on hexagonal rings of carbon atoms

- the fullerenes are finding uses as a transport mechanism for drugs to specific sites in the body, as catalysts, and as reinforcement for composite materials

- graphene is a single layer of graphite and so is just one atom thick.

- its properties, such as excellent eletrical conductivity, will help create new developments in the electronics industry in the future

8 of 12

Bonding in Metals

- the atoms in metals are closely packed together and arranged in regular layers

- you can think of metallic bonding as positively charged metal ions, which are held together by electrons from the outermost shell of each metal atom

- delocalised electrons are free to move throughout the giant metallic lattice

9 of 12

Giant Metallic Structures

- metals can be bent and shaped because the layers of atoms (or positivley charges ions) in a giant metallic structure can slide over each other

- alloys are harder than pure metals because the regular layers in a pure metal are distorted by atoms of different sizes in an alloy

- delocalised electrons in metals enable electricity and thermal energy to be transferred through a metal easily

10 of 12


- nanoscience is the study of small particles that are between 1 and 100 nanometres in size

- nanoparticles may have properties different from those for the same materials in bulk, this arises because nanoparticles have a high surface area to volume ration with a high percentage of their atoms exposed at their surface

- nanoparticles may result in smaller quantities of materials, such as catalysts, being needed for industrial processes

11 of 12

Applications of Nanoparticles

- new developments in nannoparticulate materials are very exciting and could improve many aspects of modern life

- the increased use of nanoparticles needs more research into possible issues that might arise in terms of health and the environment

12 of 12


No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Atoms and compounds resources »