Using data from the graph estimate, for this electron, its momentum and the uncertainty in its momentum.

p = 2.0 x 10-23 Ns; Δp = 2.6 x 10-25 Ns

A sample contains an amount of radioactive material with a half-life of 3.5 days. After 2 weeks the fraction of the radioactive material remaining is A. 94 %. B. 25 %. C. 6 %. D. 0 %.

The energy of α-particles in α-decay and the energy of γ-rays in γ-decay are discrete. This provides evidence for the existence of A. nuclear energy levels. B. neutrinos. C. atomic energy levels. D. isotopes.

An electron is accelerated from rest through a potential difference of 1250 V. Determine the associated de Broglie wavelength of the accelerated electron.

When a nucleus undergoes radioactive β+ decay, the change in the number of particles in the universe is A. 0. B. 1. C. 2. D. 3.

Light of frequency 8.7 × 1014 Hz is incident on the surface of a metal in a photocell. The surface area of the metal is 9.0 × 10–6 m2 and the intensity of the light is 1.1 × 10–3 W m–2. Determine the maximum possible photoelectric current in the photocell.

2.7 nA

The diagram below shows some of the energy levels available to an electron in a caesium atom. Photons of energy 0.9 eV pass through a sample of low pressure caesium vapour. Which of the following gives the energy transition of the electron when a photon is absorbed? A. From –3.9 eV to 0 B. From –2.5 eV to –1.6 eV C. From –1.6 eV to –2.5 eV D. From 0 to –3.9 eV

Which of the following is a valid statement? A. A measurement that is not precise can be accurate. B. A measurement that is precise is always accurate. C. A measurement that is not precise will always be

inaccurate. D. Repeated measurements will always increase accuracy and precision.

Light of frequency 8.7 × 1014 Hz is incident on the surface of a metal in a photocell. The surface area of the metal is 9.0 × 10–6 m2 and the intensity of the light is 1.1 × 10–3 W m–2.

The maximum kinetic energy of photoelectrons released from the metal surface is 1.2 eV. Calculate the value of the work function of the metal.

2.4 eV

A volume is measured to be 52 mm3. This volume in m3 is A. 5.2 × 103 m3. B. 5.2 × 101 m3. C. 5.2 × 10–1 m3. D. 5.2 × 10–8 m3.

A clean metal surface in a vacuum is illuminated with monochromatic light, resulting in the emission of electrons from the surface.

On the axes, sketch a graph to show how the maximum kinetic energy KE of the electron varies with the intensity I of the light.

The magnitude of the mass of the universe is of the order of A. 1020 kg. B. 1030 kg. C. 1040 kg. D. 1050 kg.

A proton is confined within a nucleus. What is the order of magnitude of the uncertainty in its momentum? A. 10–30 Ns B. 10–20 Ns C. 10–10 Ns D. 1 Ns

The diagram represents the principal lines in the visible spectrum of atomic hydrogen.

Calculate the difference in energy in eV between the energy levels in the hydrogen atom that give rise to the red line in the spectrum.

The half-life of iodine-124 is 4.2 days. A freshly prepared sample of the isotope has an activity of 810 Bq. Determine the activity of the sample after 6.0 days.

In 1924, Davisson and Germer carried out an experiment in which electrons were accelerated through a potential difference of 54 V. The electrons were scattered at the surface of a nickel crystal. Calculate the de Broglie wavelength of the electrons.

The rest mass of a proton is 938 MeV c–2. The energy of a proton at rest is A. 9.38 J. B. 9.38 × 108 × (3 ×108)2 J. C. 9.38 × 108 eV. D. 9.38 × 108 × (3 × 108)2 eV.