### Z – N

```Two samples of radioactive substances
X and Y have the same initial activity.
The half-life of X is T and the half-life of
Y is 3T. After a time of 3T the ratio of
the amounts of X to Y is
A.
B.
C.
D.
8.
4.
1/4.
1/8.
The process by which a heavy nucleus
splits into two lighter nuclei is known as
A. fission.
B. fusion.
D.
artificial (induced) transmutation.
Radium-226 decays with the emission of
Complete the nuclear reaction equation.
Which of the following provides evidence for
the existence of atomic energy levels?
A. The absorption line spectra of gases
B. The existence of isotopes of elements
C. Energy release during fission reactions
D. The scattering of α -particles by a thin
metal film
The mass of a nucleus of
rutherfordium-254 is 254.1001 u.
Calculate the mass in GeV c–2.
236.7
Nuclide X has a half-life of 1 day and nuclide
Y has a half-life of 5 days. In a particular
sample, the activities of X and Y are found
to be equal.
When the activity is tested again after 10
days, the activity will be:
A.
B.
C.
D.
entirely due to nuclide X.
due equally to nuclides X and Y.
mostly due to nuclide X.
mostly due to nuclide Y.
In a fission reaction, 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?
Total mass
A.
B.
C.
D.
Mf > Mi
Mf > Mi
Mf < Mi
Mf < Mi
Total binding
energy
Ef < Ei
Ef > Ei
Ef < Ei
Ef > Ei
A nucleus of thallium-206 (Tl-206)
nucleus of lead-206 (Pb-206). In the
reaction equation below, identify the
proton number Z of lead and the particle
x.
Z: 18 or 20;
x: neutrino/antineutrino;
The Geiger-Marsden alpha particle
scattering experiment provides
evidence for the existence of
A.
B.
C.
D.
atomic nuclei.
neutrons.
protons.
nuclear energy levels.
The main source of the Sun’s
energy is
A.
B.
C.
D.
chemical reaction.
nuclear fusion.
nuclear fission.
The relationship between proton
number Z, neutron number N and
nucleon number A is
A.
B.
C.
D.
A = Z – N.
Z = A + N.
N = A – Z.
N = A +Z.
A radio-isotope has an activity of
400 Bq and a half-life of 8 days. After
32 days the activity of the sample is
A.
B.
C.
D.
200 Bq.
100 Bq.
50 Bq.
25 Bq.
Calculate the number x of neutrons produced.
3
2.5 eV
Calculate the energy, in eV, of a photon of
light of wavelength 490 nm.
The binding energy of a nucleus is defined to
be the
A. energy released when a nucleus is formed from
its individual constituents.
B. energy released when the nucleus is separated
into its individual constituents.
C. total energy of the nucleus.
D. total energy of the protons inside the nucleus.
```