Zusammenfassung der Ressource
Chapter 2: Atoms
- Dilution of coloured substances
- Potassium manganate crystals dissolve in water- purple solution is formed
- When diluted, colour fades but doesn't dissapear until many dilutions
- Large number of particles of Potassium Manganate in very small amount of solid. Particles of K Manganate must be very small
- Diffusion
- Particles spreading to fill space
- Example
Anmerkungen:
- 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
- Takes place in liquids also, but slower
Anmerkungen:
- Because liquids are closely packed together and move more slowly than in a gas.
- Atoms and molecules
- Atoms are made up of sub-atomic particles
Anmerkungen:
- 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
- Molecules are made up of 2+ atoms covalently bonded together
Anmerkungen:
- 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.
- Elements, compounds and mixtures
- Elements
Anmerkungen:
- Elements have different, individual, chemical properties.
- Iron Filings
Anmerkungen:
- Element,
Grey Powder
Attracted to magnet
Reacts with HCl to form H gas
- Sulphur
Anmerkungen:
- Element,
Yellow Powder
Not magnetic
Does not react with HCl
- Mixture
- Iron and sulphate
Anmerkungen:
- Mixture
Mix of grey and yellow powder
Iron attracts, Sulphur doesn't
Grey powder forms H gas with HCl. Yellow powder doesn't react
- Compounds
- Iron Sulphide
Anmerkungen:
- Compound
Dark grey solid
Not attracted to magnet
Reacts with HCl to form Hydrogen Sulfide ( H2S)