End of Topic Revision

States of matter

The three main states of matter are solid liquid and gas

A substance in "aqueous" form is a substance dissolved in a solution

Within solids, particles are in a fixed position; they vibrate in this position.

Within liquids, particles are still linked but can move and flow, they aren't in a fixed position.

Within gasses, particles move freely within the space it is held in.

The amount of energy needed for a substance to transcend it's current state of matter depends on how strong the forces are between particles within the substance

State symbols are often used in chemical equations to show the state of matter that the included substances are in

Melting points and boiling points are the exact temperatures at which a substance changes states of matter

Chemical bonds

There are three types of chemical bonds: covalent, ionic and metallic

Ionic Bonds

Ionic bonds occur between metals and non-metals. Because metals form positively charged ions, the forces between the ions in ionic bonds are electrostatic.

Several ionic bonds can bind together within giant ionic lattices. These lattices have very high melting points because electrostatic forces are incredibly strong

In ionic bonds, electrons are transferred in order to achieve a full outer shell in both elements

Covalent Bonds

Covalent bonds occur between non-metals, they share electrons.

The forces within these molecules(intramolecular forces) are weak however the forces between these bonds in a giant covalent structure(intermolecular forces) are often strong and require a large amount of energy to overcome these forces.

Diamond is an example of a giant covalent structure.

Diamond is incredibly strong because within it, each carbon atom is bonded with 4 other carbon atoms. Also, it cannot conduct electricity because of its lack of free electrons.

Graphite is a giant covalent structure and a carbon allotrope. Within it, each carbon atom is bonded to 3 other carbon atoms, allowing for each carbon atom to have a free electron.

Metallic Bonds

Metallic bonds occur between metals only

Because metals always form positive ions, the forces of attraction within these bonds are between positive metal ions and negative electrons, of which there is a "sea" of

Polymers

Polymers have very large molecules

Atoms within polymer molecules are linked to others via strong covalent bonds

Intermolecular forces between these polymer molecules are quite strong so polymers are solid at room temperature

Fullerenes (and graphene)

Fullerenes are molecules of carbon formed into structures with hollow shapes

Graphene is a single layer of graphite, meaning it it arranged with carbon atoms forming 3 bonds in a hexagonal arrangement.

Graphene is one atom thick (as it is one layer) and can conduct electricity well because of it's delocalised electrons

Buckminsterfullerene is a fullerene containing 60 carbon atoms, this particular fullerene can be used to store atoms within its hollow insside.

Carbon nanotubes are a long, cylindrical fullerene. They have high tensile strength, meaning they can be stretched and pulled without breaking. They are also good at conducting both heat and electricity.

Nanoparticles

A nanometer is 1 x (10 to the power of -9) meters

A nanoparticle contains anything from 1 to 100 nanoparticles

As the size of any particle decreases, its surface area to volume ratio increases

Nanoparticles have a large surface area to volume ratio because of their small size. This allows them to be used very efficiently as catalysts

It is possible, however, that nanoparticles can in fact absorb into the cells within our body. This may be possible but is not certain as there is a lack of research in existence about nanoparticles