Alpha decay of the The sum of the mass numbers of the products (234 4) is equal to the mass number of the parent nuclide (238), and the sum of the charges on the products (90 2) is equal to the charge on the parent nuclide.
In finance, the half-life of a mortgage is the date when half of the principal amount has been paid.
Because of the way that interest is pro-rated (as a proportion of the total, paid more towards the first part of the life of the mortgage), the mortgage half-life date is generally more distant than the chronological half-way point in the total life of the mortgage.
In science, a half-life (also, as a noun, spelled half life ) is the amount of time it takes for half of a substance or entity to undergo some specified process.
For example, the half-life of a radioactive substance is the amount of time it takes for half of its atoms to decay, and the half-life of a drug is the amount of time it takes before half of the active elements are either eliminated or broken down by the body.
This is called the half life of radioactive material or radioisotope.