Radioactivity

The video tutorial explores the discovery of radioactivity by Becquerel in 1896, detailing the types of radioactive decay: alpha, beta, and gamma. It explains the law of radioactive decay, including concepts like decay constant, half-life, and mean life. The tutorial further delves into the specifics of alpha, beta, and gamma decay, highlighting their characteristics, processes, and implications in nuclear physics.

What did Becquerel discover when he observed the blackening of a photographic plate?

• The properties of phosphorescent materials

• The impact of electric fields on compounds

• The presence of radioactive substances

• The effect of visible light on silver

Which type of decay involves the emission of helium nuclei?

• Alpha decay

• Neutron decay

• Gamma decay

• Beta decay

What is the relationship between the number of decaying nuclei and time in radioactive decay?

• It is independent

• It is logarithmic

• It is inversely proportional

• It is directly proportional

What is the SI unit of radioactive activity?

• Gray

• Rutherford

• Curie

• Becquerel

How is the half-life of a radioactive substance defined?

• The time taken for the substance to completely decay

• The time taken for the substance to reduce to one-fourth of its initial value

• The time taken for the substance to reduce to half of its initial value

• The time taken for the substance to double its initial value

What happens to a nucleus during alpha decay?

• It absorbs a neutron

• It emits an alpha particle

• It emits a gamma ray

• It emits a beta particle

In alpha decay, what is the daughter nucleus?

• The original nucleus

• A nucleus with two fewer protons and neutrons

• A nucleus with two more protons and neutrons

• A nucleus with the same number of protons and neutrons

What is emitted during beta minus decay?

• A positron

• A neutron

• A proton

• An electron

What is a characteristic of gamma rays?

• They are deflected by magnetic fields

• They have a positive charge

• They can penetrate thick lead

• They travel in straight lines

What role do neutrinos play in beta decay?

• They have significant mass

• They are not deflected by electric fields

• They are easily detected

• They carry charge