Radioisotope

Radioactive decay is a process in which an unstable nucleus becomes more _____ by emitting radioactive radiation.

The three types of nuclear radiation in increasing order of penetrating power are ____. 

• Alpha, beta, gamma 

• Gamma, beta, alpha

• Alpha, gamma, beta

• Gamma, alpha, beta

What is X ?

• Electron

• Neutron

• Helium

• Oxygen

Radioisotope Uranium-238 decays to Thorium-234 as shown in the equation above. What is X?

• Proton

• Neutron

• Alpha particle

• Beta particle

The half-life is the time taken for the activity to ____ to become half of the initial value

Based on the graph, what is the half life of the sample?

• 0.5 hour

• 1.0 hour

• 1.5 hour

• 2.0 hour

A radioactive substance has a half life of 8 days. What is the numbers of days for the substance to become 25% of the initial value ?

• 3 days

• 5 days

• 8 days

• 16 days

The half-life of Radon-222 is 4 days. If the initial mass of radon is 20g, what is the mass decayed after 12 days?

• 2.5g

• 5.0g

• 15.0g

• 17.5 g

In a series of reactions, two deuterons combine to form a helium nucleus. What is the name of this process?

• Nuclear fusion

• Nuclear reaction

• Chain reaction

• Nuclear fission