What is radioactivity?
The spontaneous emission of radiation from the nucleus of an unstable atom.
What are the three main types of radioactive decay?
Alpha (α), Beta (β), and Gamma (γ) decay.
What is alpha decay?
A process where an unstable nucleus emits an alpha particle (2 protons and 2 neutrons), decreasing its atomic number by 2 and mass number by 4.
What is beta decay?
A process where a neutron converts into a proton, emitting a beta particle (electron) and an antineutrino.
What is gamma decay?
The emission of gamma rays from an excited nucleus without changing the number of protons or neutrons.
Which type of radiation is the most penetrating?
Gamma radiation.
What can stop alpha particles?
A sheet of paper or human skin.
What can stop beta particles?
A few millimeters of aluminum.
What can reduce gamma radiation?
Thick lead or concrete.
What is half-life?
The time taken for half the nuclei in a radioactive substance to decay.
Does half-life depend on external factors like temperature or pressure?
No, it is constant for a given isotope.
What is a Geiger-Müller counter used for?
Measuring the rate of radioactive decay.
What is background radiation?
Low-level radiation from natural and artificial sources present in the environment.
Give examples of natural sources of background radiation.
Cosmic rays, rocks, soil, and living organisms.
Give examples of artificial sources of background radiation.
Medical X-rays, nuclear power plants, and fallout from nuclear weapons.
What is radioactive contamination?
The unwanted presence of radioactive substances on surfaces or materials.
What is irradiation?
Exposure to radiation without coming into direct contact with the radioactive source.
How is radioactive decay different from a chemical reaction?
It involves changes in the nucleus, not electron arrangements, and is not affected by chemical conditions.
What is a nuclear equation?
A representation of a radioactive decay process showing changes in atomic and mass numbers.
Why are radioactive isotopes used in medicine?
For diagnosis and treatment, such as in PET scans and radiotherapy.
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