DP Physics Questionbank

Description

Nature of science:

Observation and deduction: Observations of stellar spectra showed the existence of different elements in stars. Deductions from nuclear fusion theory were able to explain this. (1.8)

Understandings:

• The Jeans criterion
• Nuclear fusion
• Nucleosynthesis off the main sequence
• Type Ia and II supernovae

Applications and skills:

• Applying the Jeans criterion to star formation
• Describing the different types of nuclear fusion reactions taking place off the main sequence
• Applying the mass–luminosity relation to compare lifetimes on the main sequence relative to that of our Sun
• Describing the formation of elements in stars that are heavier than iron including the required increases in temperature
• Qualitatively describe the s and r processes for neutron capture
• Distinguishing between type Ia and II supernovae

Guidance:

• Only an elementary application of the Jeans criterion is required, ie collapse of an interstellar cloud may begin if 
• Students should be aware of the use of type Ia supernovae as standard candles

Aims:

• Aim 10: analysis of nucleosynthesis involves the work of chemists

Directly related questions

• 16N.3.HL.TZ0.24a: Describe how some white dwarf stars become type Ia supernovae.
• 16N.3.HL.TZ0.24b: Hence, explain why a type Ia supernova is used as a standard candle.
• 16N.3.HL.TZ0.24c: Explain how the observation of type Ia supernovae led to the hypothesis that dark energy exists.
• 17M.3.HL.TZ1.16a:

  Outline, with reference to star formation, what is meant by the Jeans criterion.

• 17M.3.HL.TZ1.16b:

  In the proton–proton cycle, four hydrogen nuclei fuse to produce one nucleus of helium releasing a total of 4.3 × 10^–12 J of energy. The Sun will spend 10¹⁰ years on the main sequence. It may be assumed that during this time the Sun maintains a constant luminosity of 3.8 × 10²⁶ W.

  
  Show that the total mass of hydrogen that is converted into helium while the Sun is on the main sequence is 2 × 10²⁹ kg.

• 17M.3.HL.TZ1.16c:

  Massive stars that have left the main sequence have a layered structure with different chemical elements in different layers. Discuss this structure by reference to the nuclear reactions taking place in such stars.

• 20N.3.HL.TZ0.22e: Eta Aquilae A was on the main sequence before it became a variable star. Compare, without...
• 20N.3.HL.TZ0.23: In 2017, two neutron stars were observed to merge, forming a black hole. The material released...
• 17N.3.HL.TZ0.20a:

  The Sun is a second generation star. Outline, with reference to the Jeans criterion (M_J), how the Sun is likely to have been formed.

• 18M.3.HL.TZ1.18a:

  Describe the formation of a type Ia supernova.

• 18M.3.HL.TZ1.18b.i:

  Show that the distance to the supernova is approximately 3.1 × 10¹⁸ m.

• 18M.3.HL.TZ1.18b.ii:

  State one assumption made in your calculation.

• 18M.3.HL.TZ2.18a:

  Outline, with reference to the Jeans criterion, why a cold dense gas cloud is more likely to form new stars than a hot diffuse gas cloud.

• 18M.3.HL.TZ2.18b:

  Explain how neutron capture can produce elements with an atomic number greater than iron.

• 21N.1.SL.TZ0.30: Which is correct for a black-body radiator? A.  The power it emits from a unit surface area...
• 18N.3.HL.TZ0.17c: The Great Nebula is located in Orion. Describe, using the Jeans criterion, the...
• 19M.3.HL.TZ2.21b: Describe the r process which occurs during type II supernovae nucleosynthesis.
• 19M.3.HL.TZ1.19a.i: Describe the mechanism of formation of type I a supernovae.
• 19M.3.HL.TZ1.19a.ii:

  Describe the mechanism of formation of type II supernovae.

• 19M.3.HL.TZ2.21a: Explain the formation of a type I a supernova which enables the star to be used as a standard...
• 19N.3.HL.TZ0.17a:

  Proxima Centauri is a main sequence star with a mass of 0.12 solar masses.

  Estimate $\frac{\mathrm{lifetime} \mathrm{on} \mathrm{main} \mathrm{sequence} \mathrm{of} \mathrm{Proxima} \mathrm{Centauri}}{\mathrm{lifetime} \mathrm{on} \mathrm{main} \mathrm{sequence} \mathrm{of} \mathrm{Sun}}$.

• 19N.3.HL.TZ0.17b: Describe why iron is the heaviest element that can be produced by nuclear fusion processes inside...
• 19N.3.HL.TZ0.17c:

  Discuss one process by which elements heavier than iron are formed in stars.