Chapter 1

Question 1

Filtration

Answer 1

Used to separate a solid and a solution. Using a conical flask, filtration paper and a funnel. Pour the mixture into the funnel, which contains the filtration paper. The liquid solution will be allowed to pass through, while the solid is captured in the filtration paper.

Question 2

Atomic Structure

Answer 2

Atoms all have a tiny central nucleus, surrounded by orbiting electrons. The nucleus is made up of protons and neutrons, and is where all the mass of the atom is. The electrons orbit in shells - different shells are different energy levels. The higher the energy level, the further away from the nucleus the electron is.

Question 3

Crystallisation

Answer 3

Used to separate a solvent and a dissolved solute. Begin with filtration to remove any solid / excess solute. Then pour mixture into an evaporating basin and place evaporating basin in a water bath above a lit bunsen burner. Watch solution and remove when solution is half evaporated / crystals begin to form. Leave to cool for 24 hours.

Question 4

Distillation

Answer 4

Used to collect the solvent (e.g. water) from a solution. Solution is heated in a closed flask - the evaporated solvent cannot escape. The vapour rises and enters a condenser, where cold water flowing around the condensing tube in a jacket lowers the temperature so that the vapour condenses and runs down the tube into a beaker to be collected. Any dissolved solute will remain in the bottom of the original flask.

Question 5

Fractional distillation

Answer 5

Used primarily to separate different levels of crude oil. The oil is heated, and the substances within it rise into the fractionating column. How high they go depends on their boiling point: the higher the boiling point, the higher it goes. When the substance reaches the point at which it begins to cool, it runs down a separate tube to be collected.

Question 6

Paper chromatography

Answer 6

Used to separate and identify the substances in a solution. Uses how well the various compounds in the mixture dissolve in the chosen solvent. Pencil line drawn on a strip of chromatography paper, then dots of solution dabbed onto the line (using a capillary tube). The strip of paper is then place in a beaker, and the bottom of it is held in the solvent. The pencil line is not submerged, otherwise the solution would dissolve. The solvent travels up the paper, carrying the different compounds in the solution with it, and separating them out based on their solubility. The more soluble a compound is, the further up the paper it travels.

Question 7

Dalton’s ideas about the atom

Answer 7

Atoms cannot be divided or split. They are the smallest thing possible.

Question 8

Thomson’s ideas about the atom

Answer 8

Discovery of the electron
Plum Pudding model

Question 9

Rutherford’s ideas about the atom

Answer 9

Alpha Particle Scattering experiment
Discovery of the nucleus
Nuclear model

Question 10

Bohr’s ideas about the atom

Answer 10

Electrons orbit the nucleus in shells

Question 11

Chadwick’s ideas about the atom

Answer 11

Neutrons in the nucleus
Explained the mass of atoms

Question 12

Ions

Answer 12

Atoms that have lost or gained electrons and now carry a charge

Question 13

Isotopes

Answer 13

Atoms with the same number of protons and electrons (no charge), but different number of neutrons