Physics 30 Unit D

J.J. Thomson used a cathode ray tube to find what particle in the atom?

• Proton
• Neutron
• Electron

An absorption spectrum is produced from electrons within an element ________ and excited state as they _______ energy.

• moving up to; absorb
• moving up to; release
• dropping down from; absorb
• dropping down from; release

Constructive and destructive interference of electrons helps support the ______ model.

• Bohr
• nuclear
• billiard model
• wave mechanical

Which statement best explains tracks W and Y?

• Both tracks are electrons
• Both tracks are protons
• Track W is the proton and Y is the electron
• Track W is the electron and Y is the proton

A neutron decays to produce a beta-negative particle and a(n)

• electron and proton
• proton and antineutrino
• neutrino and proton
• antineutrino and alpha particle

In the standard model, the particle considered to be an elementary particle is a(n)

• proton
• neutron
• electron
• alpha particle

Cobolt-60 decays by emitting a beta negative particle and a gamma photon. Which equation describes the decay of cobolt-60?

• A
• B
• C
• D

If the half life of cobolt-60 is 5.2 years, what percentage is remaining after 15.6 years?

• 2.72
• 12.5
• 79.4
• 126

The half life of iodine-131 is 8.040 days. What percentage of an iodine-131 sample will remain after 40.20 days?

• 312.5%
• 31.25%
• .3125%
• 3.125%

Uranium-238  decays into  Thorium-234  by emitting .........

• an alpha particle
• a beta particle
• gamma rays
• visible light