O2- stands for superoxide anion, S2- stands for sulfide anion, H- stands for hydrogen anion, and Na+ stands for sodium this all ions possess the electron configuration of noble gas because each of them (O2-, S2-, H-, and Na+) has a full outer shell.
the temperature is decreased
Answer:
A chemical change occurs when the reactants chemical compositions have changed
Explanation:
a change in colour, change in temperature, change in smell, formation of a precipitate, or the formation of gas bubbles
Hopes this helps
I think its B but im not sure...