atomic structure

• what is an atom?

  the smallest part of an element that can exist
• what is an element?


  an element is a substance made up of atoms with all the same atomic number
• what is in a nucleus of an atom?

  Protons and neutrons
• what orbits the nucleus of the atom on the energy shellls?

  Electrons
• what is the size of the nucleus?

  the radius of the nucleus is 1 x 10 to the power of -14m as it is 1/10,000 of the atom radius
• what is the size of the atom?


  the atom has a radius of 0.1 nanometres(1 x 10 -10m)
• what is the relative masses of the sub atomic particles?

  the electron has a mass of 0, the proton and neutron has a mass of 1
• what are the relative charges of the sub atomic particles?


  the electron has a charge of -1, the proton has a charge of +1 and the neutron has a charge of 0.
• the number of protons equal the number of electrons as they have equal but opposite charges.
• the atomic number is the protons and neutrons in the nucleus of an atom
• what are isotopes?


  Atoms of the same element with different numbers of neutrons but he same atomic number.
• what is the relative atomic mass?

  relative atomic mass = sum of isotope abundance x isotope mass number divided by the total abundance
• what are compounds? 


  compounds are two or more elements chemically bonded together.
• what are mixtures?


  mixtures are two or more elements that are not chemically bonded together
• what happens during a chemical reaction?

  Chemical bonds are broken and new bonds are formed, resulting in the rearrangement of atoms to create new substances.
• compounds can only be separated using chemical reactions
• mixtures can be separated using physical methods.
• explain how to carry out filtration


  fold filter paper into a cone and use a funnel to separate insoluble solids from liquids
• explain the process of evaporation


  pour solution into an evaporating dish

  gently heat the evaporating dish

  keep heating until all is left is dry crystals
• what is the problem with filtration?


  filtration cannot separate soluble solids from liquids, only insoluble solids from liquids
• what is the evaporation?


  evaporation can only be used if the solid doesn't decompose
• in a physical method , no new substances are made