If the half-life of a radioisotope is 10,000 years, the amount remaining after 20,000 years is
none
half
a fourth
double
answer is c

Considering the half-life of 10,000 years, after 20,000 years we will have a fourth of the remaining amount.

Explanation:

The half-time is the time a radioisotope takes to decay and lose half of its mass. Therefore, we can make the following scheme to know the amount remaining after a period of time:

Time Amount

t=0x

t=10,000 yearsx/2

t=20,000 yearsx/4

During the first 10,000 years the radioisotope lost half of its mass. After 10,000 years more (which means 2 half-lives), the remaining amount also lost half of its mass. Therefore, after 20,000 years, the we will have a fourth of the initial amount.

chemical energy is stored in the chemical bonds of atoms and molecules. it can only be seen when it is released in a chemical reaction. when chemical energy is released, the substance from which the energy came is often changed into an entirely different substance.

this chemical reaction releases energy in the form of light and heat. chemical energy is the potential energy stored in the arrangement of atoms within molecules. breaking chemical bonds requires energy, while forming new chemical bonds releases energy.

the atp molecule can store energy in the form of a high energy phosphate bond joining the terminal phosphate group to the rest of the molecule. in this form,energy can be stored at one location, then moved from one part of the cell to another, where it can be released to drive other biochemical reactions.