c4 - atoms and radiation

• half life is the amount of time it takes for half an unstable nucleus to decay
• Contamination is one radioactive substances are found on or inside an object and irradiation is when something is exposed to radiation on the outside
• Gamma is the least harmful radiation. It is the most penetrative so will pass out of the body easily.
• Alpha is the most dangerous radiation in the body. It cannot penetrate skin and stays in the body. It is the most ionising and causes mutations which lead to cancer.
• Beta is not very harmful as it can pass out of the body
• What is peer reviewing?


  when scientists check each other’s work
• Most strongly ionising materials are less able to penetrate materials
• Ernest rutherford discovered the nucleus by firing a beam of alpha particles at thin gold foil. Most Alpha particles passed straight through.
• JJ Thompson discovered the plum pudding model of the atom claiming that the atom is a ball of positive charge with negatively charge electrons mixed in
• Ernest Rutherford discovered the nuclear model of the atom. This showed at the atoms mass is concentrated in the nucleus. Also discovered protons.
• What is an atoms overall charge?

  neutral