Particle Physics Flashcards
What is an atomic number?
It is the number of protons in an atom.
What is the Mass number or Nucleon number?
The total number of protons and neutrons in the nucleus is called the mass number.
What is an Isotope?
🔹An isotope is an atom of the same element that has an equal number of protons but different numbers of neutrons.
🔹It will also then have a different Nucleon number.
🔹Since they have an imbalance of neutrons and protons, they are unstable. This means they constantly decay and emit radiation to achieve a more stable form.
What is a nucleus?
It is a part of the atom that contains both the neutrons and the protons.
What is anti-matter?
Anti-matter particles are identical to their matter counterparts but with the opposite charge.
What are alpha particles?
🔹They are high energy particles made up of 2 protons and 2 neutrons (the same as a helium nucleus)
🔹They are usually emitted from nuclei that are too large.
What were the results of the Rutherford scattering experiment?
🔹The majority of the particles went straight through
🔻This suggested that the atom is mainly empty space.
🔹Some alpha particles deflected through small angles of <10°
🔻This suggested that there is a positive nucleus at the centre (since two positive charges would repel)
🔹Only a small number of particles deflected straight back at angles of > 90°
🔻This suggested that the nucleus is extremely small and this where the mass and charge of the atom is concentrated.
🔻It was therefore concluded that atoms consist of small dense positively charged nuclei, surrounded by negatively charged electrons.
What is the value of the atomic mass unit (u)?
1.66 × 10^-27 kg
(It is roughly equal to the mass of a single proton or neutron)
What is the mass or nucleon number?
🔹The total number of protons and neutrons in the nucleus.
What is the atomic number?
🔹It is the number of protons in a nucleus of that atom.
What values are always conserved in nuclear equations or reactions?
🔹the nucleon number
🔹the charge
🔻This means that the sum of nucleons and charge on the left hand side must equal the sum of the nucleons and charge on the right hand side.
What are beta (-) particles?
🔹They are high energy electrons emitted from the nucleus.
🔹Are emitted by nuclei that have too many neutrons.
What are beta (+) electrons?
🔹They are high energy positrons emitted from the nucleus.
🔹Are emitted by nuclei that have too many protons.
What are Gamma rays (y)?
🔹Gamma rays are high energy electromagnetic waves.
🔹are emitted by nuclei that need to loose some energy.
What is an electron neutrino?
🔹It is a type of subatomic particle with no charge and negligible mass which is also emitted from the nucleus.
