atoms molecules and mixtures

• what is the radius of an atom ?

  0.1 nanometers (1x10^-10 m)
• what is the radius of the nucleus ?

  1x10^-14 m
• mass + charge of an electron ?

  charge -1 mass 0
• mass and charge of a neutron ?

  charge 0 mass 1
• mass and charge of a proton ?

  charge +1 mass 1
• what is the overall charge of an atom ?

  neutral - 0
• what does the atomic number tell us ?

  number of protons and electrons
• what does mass number tell us ?

  mass number - atomic number = neutron number
• what is an isotope ?


  a different form of the same element with the same number of protons but a different number of neutrons
• what is an element ?

  a substance made up of atoms that all have the same number of protons in their nucleus
• what is relative atomic mass ?

  the atomic mass changes because of isotopes so its an average for the different atoms with the same number of protons but different number of neutrons. so its relative not fixed
• what is a compound?

   A pure substance made from more than one type of element chemically bonded together
• what does the term monomatic gases mean ?

  Single-atom gases (they do not form bonds)
• what is the empirical formula of potassiumoxide ?

  K2O
• describe how ice changes from solid to gas when heated

  the ice starts off compact and in fixed lattice structure, when heat is applied the particles gain more energy (thermal) this causes intermolecular force to break and particles to start moving-above 0 degrees (now in liquid) the particles are futher heated and gain more energy moveing faster and more erratically above 100 degrees.
• state is caused by how strong the force between particles is what three factors effect this force ?

  Intermolecular forces

  1. Type of molecules

  2. pressure

  3. Temperature
• what are the 4 state symbols ?

  s, l, g, aq
• what does a solid go through when turning into a gas ?

  Melting, boiling
• what does a gas go through when turning from gas to solid ?

  condesing - freezing
• what is relative formula mass ?

  mass of a compound
• what is the relative formula mass for Na2CO3

  mr(unit) = 106
• what is the percentage mass of sulfur in H2SO4 MASSES = H- 1 S-32 0-16

  total mass in mr = (1x2) + 32 + (16x4) = 98

  H = 2

  S = 32

  O = 64

  2/98 x 100 = 2.04 (% of H)

  32/98 x 100 = 32.7(% of S - ANS)

  64/98 x 100 = 65.3 (% of O)
• what is a pure substance ?

  A substance that is made up of only one type of element or compound.
• what is a formulation ?


  a substance containing precise exact amounts of components