Unit D2

Particle 1 – can only penetrate a sheet of paper or thin  metal foil

Particle 2 – can penetrate up to 3 mm of aluminum

Particle 3 – can penetrate several centimetres of lead

 

 Which of the following lists shows the particles that make up alpha, beta, and gamma radiation, respectively?

• Particles 1, 2, and 3

• Particles 1, 3, and 2

• Particles 2, 1, and 3

• Particles 3, 1, and 2

The isotope iodine-131 emits a beta-negative particle. The products of this reaction include

• A

• B

• C

• D

The isotope sodium-22 spontaneously decays to form neon-22. What are the additional particles released in order to conserve mass, energy, and momentum?

• A

• B

• C

• D

Uranium-238 is a known alpha emitter. The correct alpha-decay equation for this isotope is

• A

• B

• C

• D

Mass spectrometers are used to help date ancient artifacts. The relative amounts of carbon-12 and carbon-14 isotopes in a sample of organic material may be used to determine the age of the sample. Carbon-14 is a radioactive isotope that undergoes beta decay and has a half-life of 5 730 years.

An archaeological sample is dated using the carbon-14 dating process and is found to be 2 865 years old. What percentage of the original carbon-14 remains?

• 25.0%

• 29.3%

• 70.7%

• 75.0%

The graph shows the mass of a radioactive isotope as a function of time.

The half-life of the isotope is closest to

• 30 days

• 15 days

• 15 g

• 30 g

The mass of this isotope remaining after 2.5 half-lives is

• 11 g

• 20 g

• 25 g

• 56 g

If the radioactivity of a sample of ¹⁹₈O decreased to 1/16 of its initial value in 116 s, the half life of this radioisotope is ____ s. (give your answer to three digits e.g. include the decimal)

Given the diagram, which statement is true?

• A positive particle hits a negative particle

• Three neutral particles meet and annihilate

• A negative particle hits and sticks to a negative particle

• A neutral particle decays into a positive and a negative particle

The unknown X represents

• more neutrons

• an electron

• a neutrino

• a photon