How long will the plant have been dead when 87.5 percent of its C-14 has become N-14? After 1 half-life After 2 half-lives After 3 half-lives After 4 half-lives
50
25
12.5
6.25
percent of 14C remaining

Observation and experimentation have led many scientists to accept a theory about the origin of the universe. this theory is called the big bang theory. scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. what makes this a scientific theory? (2 points)