IBDP Physics Term topic 7

when a continuous spectrum of light is shone through an element in gaseous form, specific frequencies are preferentially absorbed (the frequencies of the element’s emission spectrum). The resulting spectrum is a continuous spectrum with dark lines (i.e. most frequencies with some specific ones missing)

• Absorption spectrum

• Emission spectrum

when an element is hot enough (given enough energy) it emits light. Analysis of this light shows that each element only emits specific frequencies (discrete spectral lines).

• Absorption spectrum

• Emission spectrum

the radiation present around us, most of which is from natural sources such as cosmic rays, rocks and soil, and vegetation. A small part is from artificial sources such as medical equipment and nuclear power.

• Background radiation

• Mass defect

the difference between the mass of a nucleus and the masses of its component nucleons. The total mass of the individual nucleons making up a nucleus must be greater than the mass of that nucleus.

• Background radiation

• Mass defect

Nuclear binding energy the energy that is needed to deconstruct a nucleus from its nucleons, and the energy that is

released when a nucleus is assembled from its component nucleons.

• True

• False

a nuclear reaction in which large nuclei are split into small nuclei and energy is released.

• Nuclear fission

• Nuclear fusion

a nuclear reaction in which the joining together (or fusing) or small nuclei into larger nuclei releases energy. Its occurs in the Sun.

• Nuclear fission

• Nuclear fusion

… constant is equal to 6.63 × 10 – 34 J s.

the spontaneous emission of ionizing radiations (alpha, beta, or gamma) from an unstable nucleus. It is a random, spontaneous process, and the rate of decay decreases exponentially with time. The nuclide decaying is the parent and the nuclide(s) formed are the daughter(s).

• Nuclear fission

• Nuclear fusion

• Radioactive decay

electrons occupy discrete energy levels with specific energies, and electrons can only move between these levels if they absorb or emit energy that equals the difference in the energy levels it is moving between.

• Energy levels

• Excited state