Info: Al(oh)3 might be an improperly capitalized: Al(OH)3 Error: Some elements or groups in the reagents are not present in the products: O Error: equation Al4C3+H2O=Al(oh)3+CH4 is an impossible reaction Please correct your reaction or click on one of the suggestions below: Al4C3 + H2O = Al(OH)3 + CH4
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=0_____________________x
t=10,000 years____________x/2
t=20,000 years___________x/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.
