Chemistry past papers

• The particles in a gas are widely spread in an irregular pattern and freely move with a high amount of energy
• Elements aren’t bonded together with other elementsL they are on their own
• Mixtures contain different elements that aren’t chemically bounded together
• Crystallisation can be used to sperate a soluble substance from a solution
• Chromatography separates mixtures and identify them according to solubility. Eg dyes
• Filtration separates an insoluble from a soluble solution
• Distillation seperates two or more soluble substances using boiling points
• The dye that moves the furthest distance is most likely to be the most soluble
• The nucleus of the atom contains the protons and neutrons
• Elements on the left side on the periodic table (metals) have a +1 charge
• Elements on the right side of the periodic table (non metals) have a -1 charge
• Ar= (mass number 1*abundance 1)+ (mass number 2* abundance 2)

  (divided by 100)