old version Radioactivity Flashcards
Who discovered two types of Radiation
Ernest Rutherford
Who were Ernest Rutherford’s workers
Hans Geiger and Ernest Marsden
What are the three types of radioactivity?
Alpha radiation (α), beta radiation (β) gamma radiation (γ).
What is activity?
Activity is the number of decays in 1 second of a source
Which type of radiation is the most penetrating?
Gamma radiation.
Why is beta radiation dangerous??
Because it has moderate ionising powers and moderate penetrating powers.
Which type of radiation cannot be penetrated by paper?
Alpha radiation.
What can ionising in a living cell do?
It can damage or kill the cell.
Can beta radiation penetrate paper?
Yes
Why are some substances radioactive?
Atoms that have an unstable nucleus try to become stable and in the process emit radiation.
Name 2 uses of radiation
Any 2 below: 1.Treating cancer 2.Sterilising medical instruments 3.Sterilising food 4.Detecting brain tumours
In Alpha and Beta decay what changes in the nucleus?
The number of protons.
Where is most of an atom’s mass located?
The small, positively charged nucleus.
what is ‘Half Life’?
Half life is the average time taken for the number of nuclei of the isotope in a sample to half.
What did the scientists think the atom was like in 1914?
Plum Pudding.
What nucleus has the least amount of charge??
The hydrogen nucleus.
Which type of radiation was stopped by paper?
Alpha radiation
What nucleus has the least amount of charge??
The hydrogen nucleus
What was the name of the Physicist who discovered that alpha and beta radiation is made up of different types of particles?
Ernest Rutherford.
In Alpha or Beta, What changes
The number of Protons in a nucleus changes
What are the 3 conclusions Rutherford made after his scattering experiment?
- Atoms are made up of empty space 2.The nucleus is positively charged therefore it repels the positive alpha particles 3.The atom must have a very small dense nucleus in the middle
What is a alpha particle made up of?
Two protons , two neutrons
Which radiation is the most dangerous in terms of ionising?
alpha
Which scientist carried out experiments where we put different materials between the radioactive substance and a detector.
Ernest Rutherford
Why are some substances radioactive?
Because electrons move about in energy levels surrounding the nucleus.
Which of the following are made up of different types of particles? Alpha, beta or gamma
Alpha and bae
Which type of radiation is the least ionising?
Gamma.
What was the proposed model of the atom before it was discovered called?
The plum pudding model.
Define Ionising
When radiation knocks an electron off an atom. This results in very reactive positive atoms.
What does the neutron in the nucleus change into with beta decay?
A proton