C1 Revision

Solid

• They are close together and are aranged in a vertical position.
• They vibrate in the same point.

Liquid

• They are close together and are aranged in a irregular pattern.
• They move around eachother.

Gas

• They are far apart and are aranged in a random pattern.
• They move quickly in all directions.

An aqueous solution is a solution in which the solvent is water.

  •There are no forces represented between the spheres.

•The size of particles and the space between them are not taken into account.

•All the particles are represented as spheres.

•The spheres represented are solid and inelastic. This means that the change in forces and collisions between particles cannot be represented fully.

•The particle model diagrams are only diagrams used to illustrate the particle model.

•For example, in the model of a solid the individual spheres represent particles that are not, themselves, solids.

•It is only when lots of these particles are arranged closely in a regular pattern that they together represent a solid.

The amount of energy needed to change state from solid to liquid and from liquid to gas depends on the strength of the forces between the particles of the substance.

The stronger the forces between the particles the higher the melting point and boiling point of the substance.

•These changes are often reversible.

•Physical changes do not change the atoms and molecules involved.

•All changes of state are physical change.

•A chemical change tends to be irreversible.

•The atoms and molecules are changed during a chemical reaction/change.

•Signs of a chemical change include:

–Colour change.

–A new substance is formed.

–Bubbles are formed.

–A temperature change occurs.

• The atomic radius is about 0.1nm.
• Atomic radius will increase if the amount of protons there are/ the further down the group an element is as there will be more electrons and so more shells.

The atom of any particle element always contains the same number of protons. E.g.                           

- Hydrogen atoms always contain 1 proton.                                                               -Carbon atoms always contain 6 protons.

The number of protons in an atom i known as its atomic number.             

The mass of each atom results almost entirely from the number of protons and neutrons that are present.

The mass number is the total number of protons and neutrons in an atom.

An element that have the same atomic number but different mass number(So different number of neutrons)