Radioactive Decay and Half-Life

What is the time required for half of the atoms in a sample of a radioactive substance to decay into a stable form?

Which type of radioactive decay emits an alpha particle (2 protons and 2 neutrons)?

What is the result of alpha decay on the atomic number and mass number of an element?

What is the result of beta-minus decay on the atomic number and mass number of an element?

What is the penetration power of alpha particles?

What is the result of beta-plus decay on the atomic number and mass number of an element?

What is the result of alpha decay on the periodic table?

What is the result of beta-minus decay on the periodic table?

What is the result of beta-plus decay on the periodic table?

What is the concept of half-life used for?

Half-Life

Half-life is the time required for half of the atoms in a sample of a radioactive substance to decay into a stable form
It is a constant and characteristic property of each radioactive isotope
Half-life is fundamental in understanding radioactive decay and is widely used in geology, archaeology, and nuclear medicine
Can be used to date objects by measuring the amount of remaining radioactive substance

Alpha and Beta Decay

Similarities

Both are types of radioactive decay processes by which unstable atomic nuclei release energy and particles to transform into more stable forms
Both result in the emission of particles from the nucleus and a change in the element

Differences

Particles Emitted

Alpha decay: emits an alpha particle (2 protons and 2 neutrons)
Beta decay: emits either an electron (beta-minus) or a positron (beta-plus)

Changes in Atomic Number and Mass

Alpha decay: decreases the atomic number by 2 and the mass number by 4
Beta-minus decay: increases the atomic number by 1 with no change in mass
Beta-plus decay: decreases the atomic number by 1 with no change in mass

Penetration Power

Alpha particles: low penetration power
Beta particles: moderate penetration power

Elemental Transformation

Alpha decay: results in an element that is two places earlier in the periodic table
Beta-minus decay: results in an element that is one place later
Beta-plus decay: results in an element that is one place earlier

Understanding radioactive decay, half-life, and types of decay (alpha and beta) in nuclear physics. Learn how half-life is used for dating objects in geology, archaeology, and nuclear medicine.