Chapter 2: Atoms

1. When diluted, colour fades but doesn't dissapear until many dilutions
2. Large number of particles of Potassium Manganate in very small amount of solid. Particles of K Manganate must be very small

1. Example

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   • Bromine from one flask to another. After 5 minutes, bromine gas has diffused between both flasks. Air and bromine particles are moving randomly and there are large gaps between particles- they can easily mix together
2. Takes place in liquids also, but slower

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   • Because liquids are closely packed together and move more slowly than in a gas.

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• Protons: Charge +1, Mass 1 Electons: -1, Mass 1/1836 Neutron: 0, 1 The only atom with no neutrons is the simplest isotype of H

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• Noble gas' (He, Neon, Radon etc.) exist as atoms at room temperature and pressure so the atom and molecule are the same. Molecule like noble gas' are called monoatomic molecules. 

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• Elements have different, individual, chemical properties.

1. Iron Filings

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   • Element,  Grey Powder Attracted to magnet Reacts with HCl to form H gas
2. Sulphur

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   • Element,  Yellow Powder Not magnetic Does not react with HCl

1. Iron and sulphate

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   • Mixture Mix of grey and yellow powder Iron attracts, Sulphur doesn't Grey powder forms H gas with HCl. Yellow powder doesn't react

1. Iron Sulphide

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   • Compound Dark grey solid Not attracted to magnet Reacts with HCl to form Hydrogen Sulfide ( H2S)