T2 exam chem

• An atom is the basic building block of chemistry
• the charge of proton is +1 and the charge of electron is -1. the charge of neutron is 0
• the mass of proton is 1 and the mass of neutron is 1. the mass of electron is 0.
• individual atoms are held together because of the attraction between proton and electron.
• the force of attraction is known as electrostatic force.
• In the late 1890s JJ-Thompson discovered the electron. His model for the atom was that electrons were scattered throughout the structure of the atom. Rutherford discovered the proton in 1909 and the nucleus in 1911. Rutherford’s most famous experiment was the gold foil experiment. James-Chadwick also worked with Rutherford and Thompson. In 1932, he proved that neutrons exist.
• pure elements means that it only consists one type of atom
• carbon = pure diamond

  nitrogen and carbon = yellow diamond

  boron and carbon = blue diamond

  hydrogen nitrogen nickel and carbon = green diamond
• seawater is 96.5% water and 3.5% salts