Is it an acid, base, or neutral? Make your own acid-base indicator from red cabbage, then test various household substances. Acids and bases are classes of materials that have different properties.

Acid-base indicators can tell us whether something is an acid, a base, or neutral. Indicators change color depending on whether they are mixed with an acid or a base. Turmeric is a powdered spice made ...

For SQA National 5 Chemistry, learn about the properties of acids and bases and how to tell them apart with this BBC Bitesize Scotland revision guide.

The pH value tells you if something is an acid, a base, or neutral. A pH of 0 indicates a high level of acidity. A pH of 7 is neutral. A pH of 14 is the most basic, or alkaline.

Blood gas testing has improved over the years thanks to advances in technology. 60 years ago, blood gas testing meant determining pO2, pCo2 and pH levels.