HELP SOS If the half-life of a radioactive substance is 950 million years and you have 96
atoms of it, how many half-lives will have passed by the time that 6 atoms of
the substance remain?
A. 5
B. 2
C. 6
D. 4

Which of the following is true about the introduction of a non-native species to an environment? (a) they usually adapt quickly so they can have a positive affect on the environment. (b) they can disrupt the environment and cause much damage and devastation to native species. (c) they usually become predators in a food chain and to keep prey populations under control. (d) because the native species are better-adapted to the environment, the non-native species always end up dying out.