Describe and calculate half life Learning Objective To be able to: Describe and calculate half life Key Words: Decay, radioactivity

Monday, 20 May 2019 Half-life Date and title in books. You need a pen, pencil & ruler. Starter Activity – 5 minutes Exam question

Learning Outcomes Draw graphs which can be used to calculate half life Target 1-9 Define half life (F/H) Target 4-9 Calculate half life using given data (H) Target 5-9 Draw graphs which can be used to calculate half life Extension: Application of Knowledge Target 8/9 Explain the significant of a half-life, linking it to the uses for different radioactive isotopes Learning Outcomes

Boardworks GCSE Science: Physics Radioactivity What is ‘radiation’? The term radiation (also known as nuclear radiation) refers to the particles or waves emitted by radioactive substances. electron Nuclear radiation comes from the nucleus of a radioactive atom. An atom has electrons orbiting the outside and a central nucleus, which is made up of protons and neutrons. proton neutron In a radioactive atom, the nucleus is unstable and so it emits particles or waves to form a more stable atom. This process is called radioactivity or radioactive decay. It is a natural and completely spontaneous process.

What is radioactive decay? Boardworks GCSE Science: Physics Radioactivity What is radioactive decay? Teacher notes This activity, summarising the three types of radiation, could be used to introduce the topic of radiation, as a plenary exercise or as a revision exercise.

What happens to radioactivity? Boardworks GCSE Additional Science: Physics Radioactive Decay What happens to radioactivity? Teacher notes This five-stage animation explains why radioactivity decreases over time.

Boardworks GCSE Additional Science: Physics Radioactive Decay What is half-life? Radioactive decay is a spontaneous process that cannot be controlled and is not affected by temperature. However, each radioactive element has its own particular decay rate, which is called the half-life. The half-life of a radioactive element is the time that it takes half the atoms in a sample to decay. For example, the half-life of the isotope iodine-131 is 8 days. This means that after 8 days half the atoms in a sample of iodine-131 have decayed. 8 days later half the remaining atoms have decayed and so on.

How is half-life calculated? Boardworks GCSE Additional Science: Physics Radioactive Decay How is half-life calculated? Teacher notes This four-stage animation explains about half-life and how to calculate it from a decay curve graph.