Answer:
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.
Water can be turned to ice if to cold gas if to hot
ice can turn to water if to hot and stay the same if to cold
gas will turn to water if to hot and freeze to ice if to cold and the pattern keeps going like that.
hope this helps
Explanation:
1 kJ = 238.85 cal and
1 cal = 0.004187 kJ
so it will be 78.9×238.85 = <em><u>1</u></em><em><u>8</u></em><em><u>,</u></em><em><u>8</u></em><em><u>4</u></em><em><u>4</u></em><em> </em>calories
78.9 Kilojoules (kJ) = 18,844 Calories (IT) (cal)
