Answer:
The correct answer is "uranium-238".
Explanation:
Uranium-238, is the most abundant isotope of the element uranium. Uranium-238 has not enough nuclear force to balance electrostatic forces between protons, and as a result, it is a radioactive isotope and its losing energy because of the spontaneous breakdown of its atomic nucleus. Uranium-238 has a half-life of 4.5 billion years and is used as fuel in nuclear reactors as well as for dating purposes.
Answer: Three
Reason/Explanation:
The cat, you and the dog are all different populations. Together, there are three populations.
-DustinBR
Exocytosis moves materials out of a cell.
Endocytosis moves materials into a cell.
Active transport uses carrier proteins. (not entirely sure about this one... check it out to be sure)
Molecules move from an area of high concentration to an area of low concentration by passive transport.