An acid is an ionic compound that produces positive hydrogen ions when dissolved in water. Acids taste sour and turn blue litmus paper red. A base is an ionic compound that produces negative hydroxide ions when dissolved in water. Bases taste bitter and turn red litmus paper blue.
I think it's the c (<span>.all the gases that surround the Earth)</span>
At first we thought atoms were just electrons and were negatively charged, but now we’ve learned that is can create different and many more substances.
