revision: Chemistry - Topic 1 Test

THE STATES AND STRUCTURE OF MATTER - 
1.1 - understand the arrangement movement and energy of the particles in each of the three states of matter.

A = GAS - freely moving particles a lot of space.

B = Liquid

C = SOLID - tightly packed particles, no movement.

Mercury and Bromine are the only two liquids at room temperature, making liquids the least common state of matter on the periodic table at room temperature.


Elements are pure substances, this means they only contain one type of atom.
Molecules are formed when two or more atom are bonded together (chemically bonded)
Compounds are molecules that contain two or more different atoms bonded together.
Mixtures are substances that contain two or more different elements or molecules that are not bonded together.

1.2 - understand how the interconversions of solids, liquids and gases are achieved and recall the names used for these interconversions.


Diffusion is the spreading of particles from an area of higher concentration to lower concentration.

S -> L = Melting
L -> G = Evaporating
G -> L = Condensing
L -> S = Freezing
G -> S = Sublimation. (For example, iodine. I2(s) [silver pellets] -> I2(g) [purple gas])

Heat must be provided for some changes of state to occur. This applies for Solids to Liquids and Liquids to Gases.

Formulas for different states ->
Example: H₂O

Vapour = H₂O(g) = water as a gas
Water = H₂O(l) = water as a liquid
Ice = H₂O(s) = water as a solid

1.3 - explain the changes in the arrangement, movement and energy of particles during these interconversions.

Water as a solid ice, will have a certain melting point where it turns to water, on a graph this is a positive gradient leading to a horizontal straight line, identifying the melting point, water then becomes steam at it's boiling point show by another gradient and another horizontal straight line identifying the boiling point.

Solids will have melting points of above room temperature, and boiling points a lot greater.
Liquids will have melting points of below room temperature and boiling points of above room temperature.
Gases will have negative melting and boiling points.

In the same groups, the different elements will have similar features but different melting and boiling points or appearances.

In group 7, the halogens, fluorine is a clear gas, while astatine appears a dark brown color. The higher you you, the less number of shells there are making them lighter in color.

1.4 -