Atomic Number & Mass Number Atomic number = the number of protons Mass number = the number of nucleons (protons & neutrons) A neutral atom has the same number of protons and electrons.
Oxygen atom
Sodium atom
Aluminium atom
Copper atom
Platinum atom
Gold atom
Lead atom
Radium atom
Uranium atom
Use your periodic table to find… 1.The number of protons in a carbon atom 2.The number of protons in a sodium atom 3.The number of neutrons in a sodium atom 4.The number of protons in a copper atom 5.The number of neutrons in a copper atom 6.The number of protons in a lead atom 7.The number of neutrons in a lead atom 8.The number of electrons in a lead atom
How many neutrons are there in a chlorine atom? Some chlorine atoms have 18 neutrons. Some have 19… They are “isotopes” of chlorine. (Chlorine–35 and Chlorine-36)
Example: Carbon Isotopes IsotopesProtonsElectronsNeutrons Carbon Carbon Carbon-14668
WORKSHEET ONE – first page only
Turning copper into gold?
Three types of Nuclear Reactions 1.Radioactive decay 2.Fusion 3.Fission
Uranium atom
Alpha Radiation ( α particle) High-speed helium nucleus (+ve charge) two protons & two neutrons Can travel up to 10% of speed of light. Range: a few centimetres Can be stopped by a sheet of paper. Can cause serious harm but cannot penetrate skin.
Beta Radiation ( β particle) High-energy electron (-ve charge) Can travel up to 90% of speed of light. Range: about 30 cm Can be stopped by a sheet of aluminium about 5 mm thick.
Gamma Radiation ( γ Ray) Electromagnetic radiation with very high energy Occurs as a result of a nucleus being left in a very excited state immediately following other types of radioactivity. Travels at the speed of light. Can penetrate through several centimetres of dense metal such as lead.
Finish WORKSHEET ONE