Radioactivity Flashcards
Describe the ‘Plum Pudding’ model of the atom.
The Plum Pudding model described the atom to consist of a positive sphere with multiple negative electrons within it.
What experiment proved the Rutherford-Bohr model of the atom?
The alpha particle scattering experiment conducted by Ernest Rutherford.
(Technically conducted by his students)
Describe the Rutherford-Bohr model of the atom.
An atom has a small, dense nucleus consisting of protons and neutrons. Tiny electrons orbit the nucleus, with a (relatively) large empty space between them and the nucleus.
What is the relative charge of a proton?
+1
What is the relative mass of a proton?
1
Where is is a proton found in an atom?
They are found in the nucleus.
What is the relative charge of an electron?
-1
What is the relative mass of an electron?
1/2,000
Where is an electron found in an atom?
They are found orbiting the atom.
What is the relative charge of a neutron?
0
What is the relative mass of a neutron?
1
Where is a neutron found in an atom?
They are found in the nucleus.
Atoms are ___ particles, they have no net charge. This means they have the same number of ___ and ___.
Atoms are neutral particles, they have no net charge. This means they have the same number of protons and electrons.
What are isotopes?
Isotopes are atoms of the same element that have different numbers of neutrons.
Give examples of natural sources of background radiation.
– Cosmic rays
– Rocks and soil
– Living beings
Give examples of artificial sources of radiation.
– Radioactive waste
– Radioactive fallout
– Medical x-rays
What are the three types of radiation?
– Alpha particles
– Beta particles
– Gamma rays
Describe an alpha particle.
– An alpha particle is a Helium nucleus.
– The charge on an alpha particle is +2.
– Alpha particles will be deflected in a magnetic and electric field.
– Alpha particles have the highest ionising ability.
Describe a beta particle.
– A beta particle is a fast moving electron.
– A beta particle is formed when a neutron in the nucleus breaks down and creates a proton and an electron. The proton remains in the nucleus and the election is ejected at high speed.
– Beta particles will be deflected in a magnetic and electric field.
– Beta particles have a moderate ionising ability.
Describe a gamma ray.
– A gamma ray is a high energy electromagnetic wave.
– The charge of a gamma ray is 0.
– Gamma rays will not be deflected in a magnetic or electric field.
– Gamma rays have the lowest ionising ability.
