When a nucleus undergoes radioactive β+ decay, the change in the number of particles in the universe is
The number of different frequencies in the emission spectrum of atomic hydrogen that arise from electron transitions between these levels is
The atom is excited so that an electron is promoted to the −0.50 eV energy level. How many different frequencies will be observed in the emission spectrum?
The reaction equation for this decay may be written as
Which of the following correctly identifies the proton number of argon-40 and the particle X?
γ, β, α
β, α, γ
α, γ, β
α, β, γ
It was predicted before it was observed.
It was difficult to detect because it is charged.
It is not part of the Standard Model.
It was difficult to detect because it has no mass.
undergoes β+ decay. The products of this decay are the β+ particle, X and Y. What are X and Y?
Total internal reflection
Placing the sample in a lead container
Placing the sample in a dark room
Decreasing the mass of the sample
Decreasing the temperature of the sample
Alpha particle scattering
The existence of isotopes
protons and neutrons
protons and electrons
neutrons and electrons
protons, neutrons and electrons
p+ + p+ → p+ + n0 + μ+
The short-range nature of the strong nuclear force
The increase of the binding energy per nucleon with proton number
The existence of quarks and leptons
The existence of alpha decay
weak nuclear force.
strong nuclear force.
A radioactive isotope has an initial activity A0 and a half-life of 1 day. The graph shows how the activity A varies with time. time.
The ratio `A_0/A_2` is equal to which of the following?
The activity of the sample after a given period of time.
The mass of the sample after a given period of time.
The activity and the mass of the sample after a given period of time.
The mass of the sample.
MeV per nucleon.
is an example of
positron and neutrino.
positron and antineutrino.
electron and neutrino.
electron and antineutrino.
the closest approach distance from charged particle scattering experiments.
the discrete energies of alpha particles from a given nuclide.
the range of energies of beta particles from a given nuclide.
the paths taken by ions in a Bainbridge mass spectrometer.
atomic energy levels.
nuclear energy levels.
nuclei having more neutrons than protons.
the existence of isotopes.
Planck’s constant is h. What is the highest frequency in the atom’s emission spectrum that is associated with these levels?
What does the quantity S x E represent?
Average energy produced in 2 s
Average power produced in 2 s.
Total energy produced in 2 s.
Maximum power produced in 2 s.
range in air.
Which of the following is a comparison of the distances of closest approach of the two alpha particles and the forces experienced by the alpha particles at the point of closest approach?
Which of the following relationships between the wavelengths is correct?
` λ1=λ2+λ3 `
where n is the neutron. Which of the following gives the value of the nucleon number A and proton number Z for the krypton (Kr)?
Photons of energy 0.9eV 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?
From -3.9eV to 0
From -2.5eV to -1.6eV
From -1.6eV to -2.5eV
From 0 to -3.9eV
Which diagram shows the emission line spectrum associated with electron transitions from energy level X?
The table shows four photons with their corresponding energies.
Each photon is incident on a hydrogen atom in its ground state. Which photons could be absorbed by the atom?
X and Y only
Y and Z only
X, Y and Z only
Which electron transition will produce a photon of the longest wavelength and which transition will produce a photon with the highest frequency?
the total mass and the total binding energy before the reaction are Mi and Ei respectively, where the binding energy is defined as a positive quantity. After the reaction the total mass is Mf and the total binding energy is Ef . Which of the following correctly compares the total masses and the total binding energies?
Which labelled electron transition gives rise to the photon with the greatest wavelength and which gives rise to the photon with the smallest wavelength?