Neutral substances are chemicals that have no properties of either acids or bases, have equal parts hydrogen and hydronium ions and don't change the color of litmus paper or other acid-base indicators. Neutral substances include water, glucose solutions and salt solutions. These chemicals have a pH of 7.0 on a scale of 14. In terms of toxicity, neutral substances are generally harmless to the touch.
Pure water has no ions in it whatsoever and serves as the main solvent in which acids and bases are dissolved. A sugar solution is made of molecules of carbon, hydrogen and oxygen atoms bound together in a crystalline pattern. A salt solution in pure water has dissolved sodium and chlorine ions.
Acids and bases have higher concentrations of either hydrogen ions with a plus charge or hydronium ions with a plus charge. Hydronium molecules consist of three atoms of hydrogen bound to one atom of oxygen. Acids have more hydrogen ions, and bases have more hydronium ions. Neutral substances have neither ion, or an equal number of both ions, to cancel out any acid or base properties.
While a neutral solution has a pH of 7.0, strong acids have pH numbers closer to zero and strong bases have pH measurements close to 14.