Which statement accurately describes a half-life?
a rock’s size is determined by half-life.
all stable and unstable elements have a half-life.
an atom of an element becomes half its original size in a half-life.
a half-life is the time required for half of a radioactive element to decay.

answer last one

Option (4)

Explanation:

The half-life of a radioactive isotope is defined as the time that is obtained by a radioactive isotope in order to decay half of its original concentration. This half is very important to know in order to calculate the age of a rock. The process of half-life is the same for all types of rocks but the duration of a half-life is different from one rock to another.

Mathematically, the half life of a radioactive isotope is given by-

where, = Radioactive half-life

= Decay constant

ln (2) = Natural log of 2

Thus, the correct answer is option (4).

the expression 15n + 2(3p) represents the amount isaiah spent buying gasoline and snacks, where n represents the price of each gallon of gasoline and p represents the cost of each snack that he bought. which statement is true about the amount isaiah spent?