Answer: 5.39
Explanation: you are adding the balloon's volume and the container's volume
Answer: True!
Explanation: As electrons that are excited move between energy levels, they emit lots and lots of energy, in fact way more energy than ground state electrons (electrons that move within the same energy level) do, thus, making them more unstable.
During a phenomenon called beta decay the neutron of the isotope uranium 237 emits/releases an electron causing an increase of atomic number. With the reference of a periodic table the "new" element is Neptunium or Np-237.