5) Atomic Physics Flashcards
Alpha particle:
A positively charged particle consisting of two protons and two neutrons. They are highly ionising, but can be stopped by a few centimetres of air.
Atom
The smallest component of an element having the chemical properties of the element, consisting of a nucleus containing combinations of neutrons and protons and one or more electrons bound to the nucleus by electrical attraction.
Electrons:
A negatively charged constituent of the atom, that are found in different energy levels, around the nucleus.
Isotopes
Atoms with the same number of protons but different numbers of neutrons. The atomic number is the same, but the nucleon number is different.
Nucleon number:
The number of protons and neutrons in an atom.
Nucleus
s a collection of particles called protons, which are positively charged, and neutrons, which are electrically neutral.
Nuclide notation:
Is a shorthand method of showing information about atoms.
Proton number:
The number of protons found in an atom of a specific element. Each element has a different proton number.
Background radiation:
The radiation that exists around us all the time
Beta particle
A high speed electron that a nucleus emits when a neutron converts into a proton. They are ionising but can be stopped by a thin sheet of aluminium.
Gamma ray
Electromagnetic radiation emitted from a nucleus. They have a very high penetrating power and require several centimetre of lead to absorb them.
Ionisation
The process in which an electron is given enough energy to break away from an atom.
Random nature of radioactive decay:
you cannot predict which nuclei in a radioactive sample will decay next, or when the next decay will occur - it is a random process.
Half life
the time taken for the nuclei of that isotope in any sample to decay
Ionising radiation:
Radiation that can cause cell mutations, damage cells and tissues, and lead to cancers.
What was rutherfords conclusion
1) Empty space
2) dense object
3) positive object
Why empty space?
Most particles passed straight through the metal foil without deflecting or bouncing back
Why dense object in the middle (nucleus)
Some bounced back at large angles impkying that they collided with a dense massive centre.
Why positive charge?
Some a particles deflected towards the source indicsting a strong replusive force
what is nuclear fission and fusion
nuclear reactants that change the nucleus of an atom to produce high amount of energy from the energy stored in the nucleus
Describe fission
Products move quickly and energy is transferred from the nucleus’s Nuclear eneergy to the nucleus KE.
The mass is less than the original because some mass is converted to wast energy.
(SPLITTING OF NUCELIS)
Why are isotopes like uranium and plutoniurm under go fission
Used in nuclear power stations
Describe nuclear fusion
Relase of energy by converting a small amount of mass into energy when two nuclei fuse. The fused nucleus has less mass than the original nuclei.
