chemistry paper 1

• What are all substances made of

  atoms.
• What is an atom?

  Smallest part of an element that can exist.
• What is an element?

  A substance that only contains one type of atom.
• What is a compound?

  2 or more elements chemically combined
• What are the reactants?

  the substances that react there on the left hand side.
• What are the products?

  The elements or compounds produced by a chemical reaction on the right hand side
• What is the equation when magnesium is burned in oxygen and magnesium oxide is produced?

  magnesium+oxygen=magnesium oxide.
• What are mixtures?

  Substances containing two or more different elements that are not chemically bonded together
• What is filtration?

  used to separate soluble solids from insoluble solids.
• What is crystallisation?

  A method used to purify a soluble solid using a saturated solution
• What is simple distillation?

  Used to obtain a solvent from a solution
• What is fractional distillation?

  used to separate mixtures in which the components have different boiling points.
• What is chromotography?

  A method used to separate a mixture of dyes
• What charge do atoms have?

  0 neutral
• What is the plum pudding model?

  It states that atoms are a ball of positive charge, with negative electrons embedded in it
• What is an atoms atomic radius?

  about 0.1nm or 1 times 10 to the power of -10 m
• How many subatomic particles are there?

  3
• What are the three subatomic particles?

  protons, neutrons, electrons
• What is the relative mass and relative charge of protons?

  mass- 1

  charge-+1
• What is the relative mass and relative charge of neutrons?

  mass-1

  charge-0
• What is the relative mass and relative charge of electrons?

  mass-very small

  charge- -1
• Where is almost all the mass of an atom located?

  nucleus
• What is most of the atom?

  empty space
• What is the formula for the number of neutrons?

  mass number - atomic number
• What are isotopes?

  elements that have the same number of protons but different number of neutrons
• What can an atom become if it gains or loses electrons?

  ions.
• What is the electron configuration in an atom?

  1st shell -2 electrons

  next two shells-8 electrons each.
• What does the electron configuration of an atom do?

  shows how electrons are arranged around a nucleus in shells.
• How did John Newlands arrange the elements?

  By atomic weight.
• What did Mendeleev do?

  left gaps in his table for unknown elements and made predictions about their properties
• What are the group 0 elements on the periodic table?

  noble gases

  full outer shell of electrons

  this means a stable electron configuration making them un-reactive non metals
• What are group 1 elements?

  alkali metals

  low melting and boiling point

  become more reactive

  low density
• What are group 7 elements?

  halogens

  seven electrons in outermost cell

  react with metals when this happens halogen atoms gains 1 electron?
• What are the three states of matter?

  solid, liquid, gas
• What is the particle model?

  model showing how particles are arranged in each of the three states of matter.
• In solids the particles?

  - have a regular arrangement

  - are very close together

  - vibrate about fixed positions
• In liquids the particles?

  Have a random arrangement

  Are close together

  Flow around each other
• In gases the particles?

  Have a random arrangement, are much further apart, move very quickly in all directions
• When a substance changes state what happens?

  particles stay the same

  way there arranged changes

  the way they move changes.
• How do we identify the state of a substance?

  melting point and boiling point can help identify a substances state.