Chemistry

• states that the mass of the products in s chemical reaction will always br equal to the mass of the reactants.

  Law of conservation of mass
• states that all samples of chemical compound contain all the elements in the same proportion.

  Law of definite composition
• states that the elements in a compound have a proportion of those chemical compounds that can be expressed in a small, whole number ratio.

  Law of multiple proportions
• started to lay down the foundations of the atomic theory.

  John dalton
• he proposed that atoms have fixed weights and definite properties.

  John dalton
• extremely small particles

  atoms
• a small, indivisible particle considered to be the basic unit of matter.

  atom
• 3 subatomic particles

  Protons

  Neutron

  Electrons
• small, negatively- charged particles

  electrons
• positively- charged particles


  protons
• He discovered protons using gold foil

  Ernest Rutherford
• He discovered protons using crookes tube with holes in the cathode

  Eugene Goldstein
• Located inside the nucleus. No charge

  Neutrons
• He discovered neutrons in 1932, using a thin sheet of beryllium with alpha particles

  James Chadwick
• equal to the number of protons inside the nucleus


  atomic number
• sum of the number of protons and the number of neutrons in the nucleus

  mass number
• atoms of the same element that have the same number of protons but different number of neutrons

  Isotopes
• an isotopes of hydrogen, has one proton but no neutron

  Protium
• has 1 proton and 1 neutron and is sometimes called heavy hydrogen

  Deuterium
• has 1 proton and 2 neutrons

  tritium
• has 6 protons and 6 neutrons 


  Carbon -12
• 6 protons and 7 neutrons

  Carbon-13
• 6 protons and 8 neutrons


  carbon-14
• made up of atoms

  molecules
• contains only two atoms and normally occur in nature


  diatomic molecules
• atoms are of the same element

  homonuclear
• they are of different elements

  heteronuclear
• contains three or more atoms


  polyatomic molecules
• atoms or molecules that have charge

  ions
• positively charged ion


  cation
• negatively charged ion

  anion
• a process that requires a filtering medium

  filtration
• solid component that remains on the filter paper

  residue
• clear liquid collected from filtration

  filtrate
• used to separate the components of mixtures based on their varying weights

  sedimentation
• separating the liquid from the solid component of a mixture

  decantation
• turning solid into gas

  sublimation
• solid to a liquid or solvent

  evaporation
• continuous cycle of evaporation and condensation of the volatile components of mixture, which have different boiling point 


  distillation
• simple but efficient technique d to separate and identify the components of a mixture

  chromatography