IB Physics

a. The Feynman diagram shows electron capture.

State and explain the nature of the particle labelled X.

[3 marks]

Answer explanation

[3 marks]

Tags

NGSS.HS-PS1-8

Two observations about the photoelectric effect are

Observation 1: For light below the threshold frequency no electrons are emitted from the metal surface.

Observation 2: For light above the threshold frequency, the emission of electrons is almost instantaneous.

Explain how each observation provides support for the particle theory but not the wave theory of light.

[4 marks]

Answer explanation

[4 marks]

Tags

NGSS.HS-PS4-3

The graphs show the variation with distance x of the square of the amplitude Ψ² of the wave function of a particle. Which graph corresponds to a particle with the largest uncertainty in momentum?

• 
• 
• 
• 

Deviations from Rutherford scattering are detected in experiments carried out at high energies. What can be deduced from these deviations?

• The impact parameter of the collision

• The existence of a force different from electrostatic repulsion

• The size of alpha particles

• The electric field inside the nucleus

A pure sample of mass m of a radioactive substance with half-life T_1/2 has an initial activity A₀.

 

What are the half-life and the initial activity of a pure sample of mass 2m of the same radioactive substance?

• A

• B

• C

• D

Tags

NGSS.HS-PS1-8

Nuclear density...

• is constant because the volume of a nucleus is proportional to its nucleon number.

• is constant because the volume of a nucleus is proportional to its proton number.

• depends on the nucleon number of the nucleus.

• depends on the proton number of the nucleus.

Electron capture can be represented by the equation

p + e^– → X + Y.

What are X and Y?

• X: proton

  Y: positron

• X: electron

  Y: positron

• X: neutron

  Y: electron antineutrino

• X: neutron

  Y: electron neutrino

Tags

NGSS.HS-PS1-8

b. Particles can be used in scattering experiments to estimate nuclear sizes. Outline how these experiments are carried out.

[2 marks]

Answer explanation

[2 marks]

Tags

NGSS.HS-PS1-8

Outline why the particles must be accelerated to high energies in scattering experiments.

[3 marks]

Answer explanation

[3 marks]

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-3

What is the order of magnitude of the mass of an electron in grams?

• 10^-16

• 10^-3

• 10^-31

• 10^-27