Answer:
The pressure decrease with the passage of time due to again dissolution of carbon-dioxide gas in the liquid solution.
Explanation:
In soft drinks, the carbon-dioxide gas is added in the drinks with high pressure because carbon-dioxide is a gas which is insoluble in soft drink at room temperature but soluble in the drinks at high pressure so when the pressure is removed from the soft drink, the carbon-dioxide gas releases in the air with the passage of time. But in close bottle , there is no place of escape so it again dissolve in the solution.
Tin-120 because an atom has to have a neutral charge. If an atom has 50 electrons it must have 50 protons unless it's an ion. Add 70 to the atomic mass because it has 70 neutrons on top of 50 protons. That equals to 120. Tin has an atomic number of 50 (meaning it has 50 protons) and it has roughly an atomic mass of about 118. If the given has 70 neutrons then it's a isotope of tin.