The answer is (3) iodine-131, treatment of thyroid disorders. The radium-226 and cobalt-60 can be used in treatment of cancer. Carbon-14 can be used in dating of once-living organisms. Uranium-238 can be used in dating of rock formation.
Find the number of protons and neutrons of that element and add them together. You might need periodic table. Hope it helps.
I think the correct answer would be the first option. As the hiker reaches the top of the mountain, the plastic bag would, most likely, expand. Before starting, the plastic bag would have a certain amount of gas particles inside. As the you hike, the pressure would decrease causing for the gas molecules to reestablish equilibrium thus pushing the bag outwards. In other words, expanding the bag. Also, base from the ideal gas equation, PV = nRT, at constant temperature and number of moles, pressure and volume are inversely related. Thus, as the pressure decreases, the volume of the system would increase accordingly.
https://www.khanacademy.org/science/chemistry/chemical-reactions-stoichiome/balancing-chemical-equations/v/balancing-chemical-equations-introduction
this will help trust me
have a good day
