Largest
K
Ca
Ga
Ge
As
Br
Kr
Smallest
Answer:
Scientific theories are testable and make falsifiable predictions. They describe the causes of a particular natural phenomenon and are used to explain and predict aspects of the physical universe or specific areas of inquiry (for example, electricity, chemistry, and astronomy).
A good theory in the theoretical sense is (1) consistent with empirical observations; is (2) precise, (3) parsimonious, (4) explanatorily broad, and (5) falsifiable; and (6) promotes scientific progress (among others; Table 1.1).
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.
