PHY003. b23 ĐL Phóng xạ

In the phenomenon of radioactivity, the quantity λ is:

• Radioactive constant.

• Wavelength.

• Radioactive period.

• Radiation.

Choose the correct statement. Radioactivity is the phenomenon of a nucleus

• emitting electromagnetic radiation

• spontaneously emitting α, β, γ rays.

• spontaneously emitting radiation and transforming into another nucleus.

• emitting radiation when bombarded by fast-moving particles.

A radioactive substance X has a radioactive constant λ. At the initial time, there are N0 nuclei of X. After time t, the remaining number of nuclei of radioactive substance X is

• N0.2^-t/T.

• N0.2-t.

• N0(1 - e-λt).

• N0(1 - λt).

Alpha radiation

• has a speed equal to the speed of light in a vacuum.

• is a stream of Z=2; A=4) He nuclei.

• is not deflected when passing through electric and magnetic fields.

• is a stream of hydrogen atom nuclei.

Which of the following is not a type of radiation?

• Gamma radiation.

• Beta plus radiation.

• Alpha radiation.

• X radiation.

Which conclusion below is incorrect?

• Radioactivity is a quantity characteristic of the strong or weak radioactivity of a quantity of radioactive substance.

• Radioactivity is a quantity characteristic of the strong or weak radioactivity of a radioactive substance.

• Radioactivity depends on the nature of the radioactive substance, directly proportional to the number of atoms of the radioactive substance.

• The radioactivity of a quantity of radioactive substance decreases over time according to the law of exponential functions.

The relationship between the half-life T and the radioactive constant λ of a radioactive substance is:

• λ=ln2/T

• λ=T/ln2

• λ=ln.T

• λ=1/ln2.T

The half-life T is the time for:

• one quarter of the nuclei of a quantity of radioactive substance to decay, transforming into another nucleus.

• one third of the nuclei of a quantity of radioactive substance to decay, transforming into another nucleus.

• one half of the nuclei of a quantity of radioactive substance to decay.

How much of a radioactive substance decays into another nucleus?

• one third

• one half

• all

• none

What is the stream of particles in beta radiation?

• electron

• positron

• neutron

• proton