5. Radioisotopes Radioisotopes are isotopes that are radioactive—they spontaneously emit energy (or radiation) when their nucleus breaks down. The term for this process is radioactive decay. When the process involves a change in the number of protons in the nucleus, the atom can change into another element. In one type of radioactive decay, a neutron in the nucleus splits into a proton and an electron. This split decreases the number of neutrons by one and increases the number of protons by one, but since protons and neutrons have approximately the same mass, the mass number stays the same. Since the number of protons changes, the atom becomes a new element.
Carbon-14 has 8 neutrons and 6 protons. When this radioisotope undergoes the radioactive decay process discussed above, it becomes nitrogen-14.
The number of protons in nitrogen-14 is?

and after water is usually warmed by the sun the water temperature raises and then evaporates .

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.