3.2.1.1.
What are the main constituents of an atom? (i.e. What does an atom consist of?)
- positively charged nucleus → comprises protons and neutrons
- electrons surround the nucleus
Nucleon def.?
- a proton or a neutron in the nucleus (the proton is a nucleon whenever it is inside the
nucleus and so is the neutron)
How are electrons held inside the atom?
- nucleus is positively charged
- electrons are negatively charged
→ electrostatic force of attraction between atoms and nucleus
Charge, charge relative to proton, mass and mass relative to proton of electron,
proton and neutron?
Isotope def.?
- atoms of the same element with diff. no. of neutrons, but same no. of protons
Use of isotopic data?
e.g.
Atomic no. def.? Symbol?
- proton number
-Z
Mass no. def.? Symbol?
- nucleon number (total no. of protons and neutrons found in the nucleus of an atom)
-A
Standard notation for isotopes (same for atoms too actually)?
Nuclide def.?
- a type of nucleus
- e.g.
, Specific charge def.? Unit?
- the charge/its mass of a particle
- unit: C/kg
- e.g.
3.2.1.2.
Strong nuclear force def.?
- the force that holds nucleons together in the nucleus
→ does this by overcoming the electrostatic force of repulsion between the
protons in the nucleus
Describe the features of the strong nuclear force? E.g. range?
1) it has a range of 3fm (so its range is the size of a nucleus) → the force
becomes negligible past 3fm
→ the strong nuclear force differs from the electrostatic force of attraction BCS
the electrostatic force between 2 charged particles has an infinite range ← it’s
just getting weaker, the further apart the atoms are
2) has the same effect between 2 protons as it does between 2 neutrons or a
proton and a neutron
3) this force is attractive from 3fm down to about 0.5fm
→ below 0.5fm it becomes repulsive, in order to ensure that the nucleons are not
being pushed into each other