Chemistry

• solid particles can’t vibrate on the spot, they have low energy as they cannot move, they have regular fixed positions
• Liquids are irregular and random particles, they have medium movement and particles slide, medium energy
• Gases can freely move and they have high energy so they move very fast
• Ice to gas is sublimation
• Gas to ice is deposition
• Soluble is a substance able to be dissolved
• Insoluble is a substance that can’t dissolve in a solvent
• Solute is a substance that is dissolved in a solution
• Solvent is a substance capable of dissolving several substances
• Filtration is separating an insoluble from a soluble solution
• Crystallisation is separating a soluble substance from a substance
• Simple distillation is separating two or more soluble substances using boiling point
• Fractional distillation is separating many different complex mixtures into fractions using boiling points
• Chromatography is separating mixtures and identifying them according to solubility to phases
• Mass number is the number on top which is number of protons + number of neutrons
• Atomic number is at the bottom and is the number of protons
• The number of protons is the same as number of electrons
• Atoms have no overall charge because they contain an equal number of positive protons and negative electrons
• The number of neutrons is the mass number minutes atomic number
• Isotopes are forms of an element that have the same number of protons but different numbers of neutrons
• Ionic bonding is the transfer of electrons to make ions between metals and non metals to obtain a full outer shell. They have strong electrostatic forces of attraction between oppositely charged ions
• Covalent bonds is the sharing of electrons in non metals to have a full outer shel. They have a shared pair of electrons
• hot water evaporates quicker than cold water because the hotter a liquid is, the more energy the particles have, so the faster the liquid will evaporate.
• Argon is 1% of dry air
• Nitrogen is the most abundant gas in dry air
• the chemical name for rust is hydrated iron oxide
• Methods of extracting metals are mining, reduction by carbon and electrolysis
• Mining can be used for copper, gold , iron, zinc, diamond,
• Reduction by carbon used for iron, tin, lead, copper
• electrolysis for sodium, calcium, magnesium, aluminium, potassium, lithium
• Gold can be extracted in its native state
• acids aee any hydrogen containing substance
• Alkalis are a basic hydroxide that produces negatively charged ions when dissolved in water
• 0-3 are strong acids
• 4-6 are weak acids
• 7 is neutral
• 8-10 are weak alkalis
• 11-14 are strong alkalis
• What is the purpose of the Ed EXL International GCS chemistry videos?

  To help students prepare for exams in Great Britain.
• What is a compound?

  A substance that contains two or more different types of atoms chemically bonded together.