4. On the periodic table, which noble gas is closest to sodium, Na? What must happen to a sodium atom in order for it to have a noble gas electron configuration?
5. When bromine gains an electron to become a bromine ion with a -1 charge, it ends up with the
noble gas electron configuration of krypton. Why doesn't it become a krypton atom?

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.

the product of the pressure and volume is also constant

your answer would be “dry”