Chemistry paper 1

• more reactive metals can replace less reactive metals from their compounds
• Order the models of the atom earliest to latest

  John Dalton- solid sphere model

  J.J Thompson - plum pudding model

  Ernest Rutherford - Nuclear model

  Niels Bohr - Planetary model
• What is radioactive decay?


  Break down of atoms by releasing energy
• The periodic table shows how elements are arranged based on increasing atomic number.
• What are the charges and masses of protons, neutrons and electrons?

  Proton: +1 , 1

  Electron: -1, 0

  Neutrons: 0 (1/2000) , 1
• What is the number on top of an element?

  Atomic mass (neutrons and protons)
• What is the number on the bottom of an element?

  Atomic number (protons)
• What is an isotope?

  Isotopes are atoms of elements which contain the same number of protons and electrons but a different number of neutrons
• What is a period on the periodic table?

  Horizontal row of elements (across)
• What is a group on the periodic table?

  Vertical columns (going down)
• Why do some particles pass through a gold sheet but not old in Rutherford's experiment?

  -Mostly empty space

  -Some alpha particles deflect as nucleus is positive
• What is filtration?

  Separation of solid particles from a liquid or gas by passing it through a porous material (filtration paper)
• What is distillation?

  Distillation is a process used to separate and purify liquids based on their different boiling points by using a bunsen burner and a glass tube
• What is present in group 1 in the periodic table?

  Alkaline metals - more reactive as you go down the group
• What is present in group 7 in the periodic table?

  Halogens - less reactive as you go down - size of atom gets bigger (less attraction)
• How do you test for hydrogen gas?


  Light a splint, place it in a glass full of hydrogen and you should hear a pop if it is present.
• How do you test for oxygen?


  Lit splint

  Blow it out

  Oxygen will relight the glowing splint
• How do you test for chlorine gas?

  Place damp blue litmus paper in some chlorine to which it will turn white (bleaches it)
• How do you test for carbon dioxide?

  Bubble some lime water which starts off clear then should turn cloudy if carbon dioxide is present.
• What is anion?


  A negatively charged ion. (cl-)
• What is an electrolyte?

  A molten liquid or solution which contains ions that move freely and be seperated
• What is electrolysis?

  Separation of a molten or dissolved ionic compound using an electrical current
• What is cation?

  A positively charged ion (Na)
• What is the cathode?

  Negative electrode
• What is an anode?

  A positive electrode
• What does OILRIG stand for?

  Oxidation Is Loss, Reduction Is Gain
• What are 3 different common strong acids?

  Hydrochloric acid (HCl)

  Sulfuric acid

  Nitric acid

  They all produce H+ ions when dissolved in water.
• What are 3 different common alkalis?

  Sodium hydroxide (NaOH)

  Lithium hydroxide (LiOH)

  Potassium hydroxide (KOH)

  These all produce OH- ions
• How are concentrated and strong acids different from eachother?

  Concentrated contain lots of H+ ions

  Strong acids fully ionise in water
• What is a solute, solution and solvent?

  Solute: Solid which dissolves

  Solvent: Liquid dissolved a solid

  Solution: Solute dissolvent in a solvent
• What is crystallisation? 


  Used to separate soluble solids from liquids (solids that do dissolve)
• What is chromatography?


  Chromatography is a technique used to separate and analyze the components of a mixture to identify colouring, drugs or fluids.
• What is exothermic?


  A reaction that releases heat to the surroundings
• What is endothermic?


  Absorbing heat from the surroundings
• What happens in a rechargeable cell?

  The chemical reaction can be reversed by connecting it to an external electrical current.
• How do you calculate percentage mass of an element?

  mass of element / mr x100
• What is avogadros number?

  6.022 x 10^23
• What is the equation for for number of moles?

  number of moles = mass / formula mass(mr)
• 1000cm3 = 1dm3
• moles = concentration x volume