Physics Criteria A final

Proton (charge and mass)

Charge: +1

Mass(Amu):1

Electron (charge and mass)

Charge: -1

Mass (Amu): 1/1840

Neutron (charge and mass)

Charge: 0

Mass (Amu): 1

Mass number

Protons + Neutrons

Atomic number

Number of protons in atom

Relative atomic mass

Average weight of the atom with the probability of isotopes

Why are some isotopes stable and some not?

When an isotope holds too many or too few neutrons to maintain its stability, the atom decays and produces radiation.

Ionizing effect of radiation

When it collides with an atom, it can completely remove an electron to form a positively charged ion that can damage biological tissues.

What do unstable atoms emit?

Ionization radiation

Sievert (Sv)

the unit for the dose of radiation that affects the human body

alpha radiation

occurs when the nucleus of an atom becomes unstable and He ²⁺ (two protons and two neutrons) are emitted to restore balance.

Beta minus radiation

If there are too many neutrons, one of the neutrons changes into a proton and sends out an electron

Beta plus radiation

If there are too many protons, one of the protons can change into a neutron and send out a positron (positive version of an electron)

STILL TO DO

State the quantity for the number of decays/ counts per second (Bq)

- Explain the nature of radioactivity, being a random process of decaying nuclei

- Explain the term half-life in relation to radioactive decay

- Solve problems involving a whole number of half lives

- Estimate the age of organic matter using the half-life of Carbon-14 (half-life of 5800 years)

- Analyse, interpret and sketch half-life curves for known radioactive isotopes

- Investigate radioactive decay using an analogue (dice, beer foam)

- Idea of decay constant as probability per round/ second of a decay/six

4.3 NUCLEAR PHYSICS

- Explain nuclear fusion and nuclear fission and construct and complete nuclear equations

- State that the mass number is conserved in a nuclear equation.

- State that energy is released when heavy elements break apart and when light elements are fused together

- Describe the basic principle of nuclear energy production

- Distinguish between a controlled and uncontrolled nuclear chain reaction

- Discuss advantages and disadvantages of radiation and nuclear energy

- Apply Einstein’s Mass-Energy equivalence equation (� = ��!)

- Discuss and evaluate (inter)national efforts to promote safe uses of nuclear energy