Why should chemical reaction be balanced​

Flourine is found to undergo 10% radioactivity decay in 366 minutes determine its halflife

What is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )

Which of the following is the correct definition of chemical energy? a. energy an object has because of its motion or position b. energy resulting from the flow of charged particles, such as electrons or ions c. energy produced from the splitting of atoms d. energy stored in chemical bonds of molecules