1. Write the chemical symbols for the element/polyatomic ions present. (Should only be 2 of them) 2. Look up their charges: in order to correctly write the symbols, each ion’s total charge must be EQUAL and OPPOSITE to each other!

Example: Lithium Oxide
Lithium is Li+1, Oxide is O-2: In order to for their charges to be equal, you must have 2 Lithiums for each Oxide present! Therefore, Li2O

it is stable as it is in group 0 which have full outer shells of electrons

the answer is d.) potassium

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.